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Jimenez-Cyrus D, Adusumilli VS, Stempel MH, Maday S, Ming GL, Song H, Bond AM. Molecular cascade reveals sequential milestones underlying hippocampal neural stem cell development into an adult state. Cell Rep 2024; 43:114339. [PMID: 38852158 DOI: 10.1016/j.celrep.2024.114339] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2023] [Revised: 04/16/2024] [Accepted: 05/23/2024] [Indexed: 06/11/2024] Open
Abstract
Quiescent adult neural stem cells (NSCs) in the mammalian brain arise from proliferating NSCs during development. Beyond acquisition of quiescence, an adult NSC hallmark, little is known about the process, milestones, and mechanisms underlying the transition of developmental NSCs to an adult NSC state. Here, we performed targeted single-cell RNA-seq analysis to reveal the molecular cascade underlying NSC development in the early postnatal mouse dentate gyrus. We identified two sequential steps, first a transition to quiescence followed by further maturation, each of which involved distinct changes in metabolic gene expression. Direct metabolic analysis uncovered distinct milestones, including an autophagy burst before NSC quiescence acquisition and cellular reactive oxygen species level elevation along NSC maturation. Functionally, autophagy is important for the NSC transition to quiescence during early postnatal development. Together, our study reveals a multi-step process with defined milestones underlying establishment of the adult NSC pool in the mammalian brain.
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Affiliation(s)
- Dennisse Jimenez-Cyrus
- Department of Neuroscience and Mahoney Institute for Neurosciences, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Vijay S Adusumilli
- Department of Neuroscience and Mahoney Institute for Neurosciences, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Max H Stempel
- Department of Neuroscience and Mahoney Institute for Neurosciences, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Sandra Maday
- Department of Neuroscience and Mahoney Institute for Neurosciences, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Guo-Li Ming
- Department of Neuroscience and Mahoney Institute for Neurosciences, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA; Department of Cell and Developmental Biology, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA; Institute for Regenerative Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA; Department of Psychiatry, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Hongjun Song
- Department of Neuroscience and Mahoney Institute for Neurosciences, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA; Department of Cell and Developmental Biology, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA; Institute for Regenerative Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA; Department of Neurosurgery, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA; The Epigenetics Institute, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA.
| | - Allison M Bond
- Department of Neuroscience and Mahoney Institute for Neurosciences, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA; Nash Family Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA; Department of Cell, Developmental and Regenerative Biology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA; Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA; Black Family Stem Cell Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA.
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2
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Wang T, Gao T, Fujisawa M, Ohara T, Sakaguchi M, Yoshimura T, Matsukawa A. SPRED2 Is a Novel Regulator of Autophagy in Hepatocellular Carcinoma Cells and Normal Hepatocytes. Int J Mol Sci 2024; 25:6269. [PMID: 38892460 PMCID: PMC11172722 DOI: 10.3390/ijms25116269] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2024] [Revised: 05/29/2024] [Accepted: 06/04/2024] [Indexed: 06/21/2024] Open
Abstract
Sprouty-related enabled/vasodilator-stimulated phosphoprotein homology 1 domain containing 2 (SPRED2) is an inhibitor of the mitogen-activated protein kinase (MAPK)/extracellular signal-regulated kinase (ERK) pathway and has been shown to promote autophagy in several cancers. Here, we aimed to determine whether SPRED2 plays a role in autophagy in hepatocellular carcinoma (HCC) cells. The Cancer Genome Atlas (TCGA) Liver Cancer Database showed a negative association between the level of SPRED2 and p62, a ubiquitin-binding scaffold protein that accumulates when autophagy is inhibited. Immunohistochemically, accumulation of p62 was detected in human HCC tissues with low SPRED2 expression. Overexpression of SPRED2 in HCC cells increased the number of autophagosomes and autophagic vacuoles containing damaged mitochondria, decreased p62 levels, and increased levels of light-chain-3 (LC3)-II, an autophagy marker. In contrast, SPRED2 deficiency increased p62 levels and decreased LC3-II levels. SPRED2 expression levels were negatively correlated with translocase of outer mitochondrial membrane 20 (TOM20) expression levels, suggesting its role in mitophagy. Mechanistically, SPRED2 overexpression reduced ERK activation followed by the mechanistic or mammalian target of rapamycin complex 1 (mTORC1)-mediated signaling pathway, and SPRED2 deficiency showed the opposite pattern. Finally, hepatic autophagy was impaired in the liver of SPRED2-deficient mice with hepatic lipid droplet accumulation in response to starvation. These results indicate that SPRED2 is a critical regulator of autophagy not only in HCC cells, but also in hepatocytes, and thus the manipulation of this process may provide new insights into liver pathology.
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Affiliation(s)
- Tianyi Wang
- Department of Pathology and Experimental Medicine, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama 700-8558, Japan
| | - Tong Gao
- Department of Pathology and Experimental Medicine, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama 700-8558, Japan
| | - Masayoshi Fujisawa
- Department of Pathology and Experimental Medicine, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama 700-8558, Japan
| | - Toshiaki Ohara
- Department of Pathology and Experimental Medicine, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama 700-8558, Japan
| | - Masakiyo Sakaguchi
- Department of Cell Biology, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama 700-8558, Japan
| | - Teizo Yoshimura
- Department of Pathology and Experimental Medicine, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama 700-8558, Japan
| | - Akihiro Matsukawa
- Department of Pathology and Experimental Medicine, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama 700-8558, Japan
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Maroli G, Schänzer A, Günther S, Garcia-Gonzalez C, Rupp S, Schlierbach H, Chen Y, Graumann J, Wietelmann A, Kim J, Braun T. Inhibition of autophagy prevents cardiac dysfunction at early stages of cardiomyopathy in Bag3-deficient hearts. J Mol Cell Cardiol 2024; 193:53-66. [PMID: 38838815 DOI: 10.1016/j.yjmcc.2024.06.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/17/2023] [Revised: 05/31/2024] [Accepted: 06/02/2024] [Indexed: 06/07/2024]
Abstract
The HSP70 co-chaperone BAG3 targets unfolded proteins to degradation via chaperone assisted selective autophagy (CASA), thereby playing pivotal roles in the proteostasis of adult cardiomyocytes (CMs). However, the complex functions of BAG3 for regulating autophagy in cardiac disease are not completely understood. Here, we demonstrate that conditional inactivation of Bag3 in murine CMs leads to age-dependent dysregulation of autophagy, associated with progressive cardiomyopathy. Surprisingly, Bag3-deficient CMs show increased canonical and non-canonical autophagic flux in the juvenile period when first signs of cardiac dysfunction appear, but reduced autophagy during later stages of the disease. Juvenile Bag3-deficient CMs are characterized by decreased levels of soluble proteins involved in synchronous contraction of the heart, including the gap junction protein Connexin 43 (CX43). Reiterative administration of chloroquine (CQ), an inhibitor of canonical and non-canonical autophagy, but not inactivation of Atg5, restores normal concentrations of soluble cardiac proteins in juvenile Bag3-deficient CMs without an increase of detergent-insoluble proteins, leading to complete recovery of early-stage cardiac dysfunction in Bag3-deficient mice. We conclude that loss of Bag3 in CMs leads to age-dependent differences in autophagy and cardiac dysfunction. Increased non-canonical autophagic flux in the juvenile period removes soluble proteins involved in cardiac contraction, leading to early-stage cardiomyopathy, which is prevented by reiterative CQ treatment.
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Affiliation(s)
- Giovanni Maroli
- Department of Cardiac Development and Remodeling, Max Planck Institute for Heart and Lung Research, 61231 Bad Nauheim, Germany.; Department of Lung Development and Remodeling, Max Planck Institute for Heart and Lung Research, 61231 Bad Nauheim, Germany..
| | - Anne Schänzer
- Institute of Neuropathology, Justus Liebig University Giessen, 35392 Giessen, Germany
| | - Stefan Günther
- Max Planck Institute for Heart and Lung Research, Bioinformatics and deep sequencing platform, Ludwigstr. 43., 61231 Bad Nauheim, Germany
| | - Claudia Garcia-Gonzalez
- Department of Cardiac Development and Remodeling, Max Planck Institute for Heart and Lung Research, 61231 Bad Nauheim, Germany.; Department of Morphology and Cell Biology, University of Oviedo, 33006 Oviedo, Spain
| | - Stefan Rupp
- Department of Pediatric Cardiology and Congenital Heart Disease, Justus Liebig University Giessen, 35392 Giessen, Germany
| | - Hannah Schlierbach
- Institute of Neuropathology, Justus Liebig University Giessen, 35392 Giessen, Germany
| | - Yanpu Chen
- Department of Cardiac Development and Remodeling, Max Planck Institute for Heart and Lung Research, 61231 Bad Nauheim, Germany
| | - Johannes Graumann
- Biomolecular Mass Spectrometry, Max Planck Institute for Heart and Lung Research, 61231 Bad Nauheim, Germany.; The German Center for Cardiovascular Research (DZHK), Partner Site Rhine-Main
| | - Astrid Wietelmann
- Magnetic Resonance Imaging Group, Max Planck Institute for Heart and Lung Research, 61231 Bad Nauheim, Germany
| | - Johnny Kim
- Department of Cardiac Development and Remodeling, Max Planck Institute for Heart and Lung Research, 61231 Bad Nauheim, Germany
| | - Thomas Braun
- Department of Cardiac Development and Remodeling, Max Planck Institute for Heart and Lung Research, 61231 Bad Nauheim, Germany.; The German Center for Cardiovascular Research (DZHK), Partner Site Rhine-Main..
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4
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Atya HB, Sharaf NM, Abdelghany RM, El-Helaly SN, Taha H. Autophagy and exosomes; inter-connected maestros in Alzheimer's disease. Inflammopharmacology 2024; 32:2061-2073. [PMID: 38564092 PMCID: PMC11136856 DOI: 10.1007/s10787-024-01466-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2024] [Accepted: 03/17/2024] [Indexed: 04/04/2024]
Abstract
Autophagy is a crucial process involved in the degradation and recycling of cytoplasmic components which are transported to the lysosomal compartment by autophagosomes. Exosomes are an important means of communication and signaling in both normal and diseased states, and they have a significant role in the transmission and propagation of proteins, especially proteins implicated in neurodegenerative disorders. Autophagy may affect exosomal processing, but whether autophagy controls the release of aggregated β-amyloid and tau proteins in exosomes of Alzheimer disease (AD) is unclear. Therefore, our study aimed to investigate how modulating autophagy affects the exosomal release of these proteins in animal models of AD. Isolated exosomes from brain tissues of 48 male albino mice were divided into four groups (Negative control, LPS, rapamycin (RAPA), and chloroquine (CQ). LC3 I and LC3 II as well as Aβ and Tau proteins levels were determined. All mice undergone Neuro-behavioral tests (Morris Water maze test, Y-maze test, and Novel Object Recognition). Both LPS and CQ groups showed reduced expression levels of LC3 II and LC3 II/LC3 I ratio. In contrast, RAPA group showed a significant increase in both LC3-II expression and LC3-II/LC3-I ratio. The levels of both Aβ & Tau in exosomes of CQ & LPS groups were higher. While RAPA group showed a significant diminished levels of tau & Aβ proteins. In conclusion, our findings suggest that autophagy alterations in AD can influence the release of Aβ and tau proteins through exosomes, which may impact the spread of misfolded proteins in AD. These results highlight a potential innovative therapeutic approach for combating AD.
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Affiliation(s)
- Hanaa B Atya
- Biochemistry and Molecular Biology Department, Faculty of Pharmacy, Helwan University, P.O. Box 11795, Cairo, Egypt.
| | - Nadia Mohamed Sharaf
- Department of Pharmacology and Toxicology, Faculty of Pharmacy and Biotechnology, German University in Cairo-(GUC), Cairo, Egypt
| | - Ragwa Mansour Abdelghany
- Department of Pharmacology and Toxicology, Faculty of Pharmacy and Biotechnology, German University in Cairo-(GUC), Cairo, Egypt
| | - Sara Nageeb El-Helaly
- Department of Pharmaceutics and Industrial Pharmacy, Faculty of Pharmacy, Cairo University, Cairo, Egypt
| | - Heba Taha
- Biochemistry and Molecular Biology Department, Faculty of Pharmacy, Helwan University, P.O. Box 11795, Cairo, Egypt
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5
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Zhang B, Sun R, Bai R, Sun Z, Liu R, Li W, Yao L, Sun H, Tang Y. G-quadruplex in mitochondria as a possible biomarker for mitophagy detection. Int J Biol Macromol 2024; 259:129337. [PMID: 38218296 DOI: 10.1016/j.ijbiomac.2024.129337] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2023] [Revised: 01/06/2024] [Accepted: 01/06/2024] [Indexed: 01/15/2024]
Abstract
Mitochondrial autophagy (mitophagy) is a key physiological process that maintains the homeostasis of mitochondrial quality and quantity. Monitoring mitophagy is of great significance for detecting cellular abnormalities and developing therapeutic drugs. However, there are still very few biomarkers specifically developed for monitoring mitophagy. Here, we propose for the first time that mitochondrial G-quadruplex may serve as a biomarker for mitophagy detection, and develope a fluorescent light-up probe AMTC to monitor mitophagy in live cells. During mitophagy, AMTC fluorescence is significantly enhanced, but once mitophagy is inhibited, its fluorescence immediately decreases. The fluorescence behavior of AMTC implicates an increase in the formation of mitochondrial G-quadruplex during mitophagy. This inference has also been supported by the other two G-quadruplex probes. Taken together, this work provides a new possible biomarker and detection tool for the study of mitophagy.
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Affiliation(s)
- Boyang Zhang
- Beijing Institute of Graphic Communication, Beijing 102600, PR China
| | - Ranran Sun
- Beijing National Laboratory for Molecular Sciences (BNLMS), State Key Laboratory for Structural Chemistry of Unstable and Stable Species, Institute of Chemistry Chinese Academy of Sciences, Beijing 100190, PR China; University of Chinese Academy of Sciences, Beijing 100049, PR China
| | - Ruiyang Bai
- Beijing National Laboratory for Molecular Sciences (BNLMS), State Key Laboratory for Structural Chemistry of Unstable and Stable Species, Institute of Chemistry Chinese Academy of Sciences, Beijing 100190, PR China
| | - Zhicheng Sun
- Beijing Institute of Graphic Communication, Beijing 102600, PR China
| | - Ruping Liu
- Beijing Institute of Graphic Communication, Beijing 102600, PR China.
| | - Wenchao Li
- Senior Department of Pediatrics, The Seventh Medical Center of Chinese People's Liberation Army General Hospital, Beijing, PR China.
| | - Li Yao
- Beijing National Laboratory for Molecular Sciences (BNLMS), State Key Laboratory for Structural Chemistry of Unstable and Stable Species, Institute of Chemistry Chinese Academy of Sciences, Beijing 100190, PR China; University of Chinese Academy of Sciences, Beijing 100049, PR China
| | - Hongxia Sun
- Beijing National Laboratory for Molecular Sciences (BNLMS), State Key Laboratory for Structural Chemistry of Unstable and Stable Species, Institute of Chemistry Chinese Academy of Sciences, Beijing 100190, PR China; University of Chinese Academy of Sciences, Beijing 100049, PR China.
| | - Yalin Tang
- Beijing National Laboratory for Molecular Sciences (BNLMS), State Key Laboratory for Structural Chemistry of Unstable and Stable Species, Institute of Chemistry Chinese Academy of Sciences, Beijing 100190, PR China; University of Chinese Academy of Sciences, Beijing 100049, PR China
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6
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Zhang T, Cui M, Li Y, Cheng Y, Gao Z, Wang J, Zhang T, Han G, Yin R, Wang P, Tian W, Liu W, Hu J, Wang Y, Liu Z, Zhang H. Pax transactivation domain-interacting protein is required for preserving hematopoietic stem cell quiescence via regulating lysosomal activity. Haematologica 2023; 108:2410-2421. [PMID: 36924252 PMCID: PMC10483346 DOI: 10.3324/haematol.2022.282224] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2022] [Accepted: 03/03/2023] [Indexed: 03/18/2023] Open
Abstract
Hematopoietic stem cells (HSC) maintain lifetime whole blood hematopoiesis through self-renewal and differentiation. In order to sustain HSC stemness, most HSC reside in a quiescence state, which is affected by diverse cellular stress and intracellular signal transduction. How HSC accommodate those challenges to preserve lifetime capacity remains elusive. Here we show that Pax transactivation domain-interacting protein (PTIP) is required for preserving HSC quiescence via regulating lysosomal activity. Using a genetic knockout mouse model to specifically delete Ptip in HSC, we find that loss of Ptip promotes HSC exiting quiescence, and results in functional exhaustion of HSC. Mechanistically, Ptip loss increases lysosomal degradative activity of HSC. Restraining lysosomal activity restores the quiescence and repopulation potency of Ptip-/- HSC. Additionally, PTIP interacts with SMAD2/3 and mediates transforming growth factor-β signaling-induced HSC quiescence. Overall, our work uncovers a key role of PTIP in sustaining HSC quiescence via regulating lysosomal activity.
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Affiliation(s)
- Tong Zhang
- The State Key Laboratory Breeding Base of Basic Science of Stomatology and Key Laboratory of Oral Biomedicine Ministry of Education, School and Hospital of Stomatology, Medical Research Institute, Wuhan University, Wuhan, China; Frontier Science Center for Immunology and Metabolism, Wuhan University, Wuhan
| | - Manman Cui
- The State Key Laboratory Breeding Base of Basic Science of Stomatology and Key Laboratory of Oral Biomedicine Ministry of Education, School and Hospital of Stomatology, Medical Research Institute, Wuhan University, Wuhan, China; Frontier Science Center for Immunology and Metabolism, Wuhan University, Wuhan
| | - Yashu Li
- The State Key Laboratory Breeding Base of Basic Science of Stomatology and Key Laboratory of Oral Biomedicine Ministry of Education, School and Hospital of Stomatology, Medical Research Institute, Wuhan University, Wuhan, China; Frontier Science Center for Immunology and Metabolism, Wuhan University, Wuhan
| | - Ying Cheng
- The State Key Laboratory Breeding Base of Basic Science of Stomatology and Key Laboratory of Oral Biomedicine Ministry of Education, School and Hospital of Stomatology, Medical Research Institute, Wuhan University, Wuhan, China; Frontier Science Center for Immunology and Metabolism, Wuhan University, Wuhan
| | - Zhuying Gao
- The State Key Laboratory Breeding Base of Basic Science of Stomatology and Key Laboratory of Oral Biomedicine Ministry of Education, School and Hospital of Stomatology, Medical Research Institute, Wuhan University, Wuhan
| | - Jing Wang
- The State Key Laboratory Breeding Base of Basic Science of Stomatology and Key Laboratory of Oral Biomedicine Ministry of Education, School and Hospital of Stomatology, Medical Research Institute, Wuhan University, Wuhan
| | - Tiantian Zhang
- The State Key Laboratory Breeding Base of Basic Science of Stomatology and Key Laboratory of Oral Biomedicine Ministry of Education, School and Hospital of Stomatology, Medical Research Institute, Wuhan University, Wuhan, China; Frontier Science Center for Immunology and Metabolism, Wuhan University, Wuhan
| | - Guoqiang Han
- The State Key Laboratory Breeding Base of Basic Science of Stomatology and Key Laboratory of Oral Biomedicine Ministry of Education, School and Hospital of Stomatology, Medical Research Institute, Wuhan University, Wuhan, China; Frontier Science Center for Immunology and Metabolism, Wuhan University, Wuhan
| | - Rong Yin
- Department of Hematology, Zhongnan Hospital, Wuhan University, Wuhan
| | - Peipei Wang
- The State Key Laboratory Breeding Base of Basic Science of Stomatology and Key Laboratory of Oral Biomedicine Ministry of Education, School and Hospital of Stomatology, Medical Research Institute, Wuhan University, Wuhan, China; Frontier Science Center for Immunology and Metabolism, Wuhan University, Wuhan
| | - Wen Tian
- The State Key Laboratory Breeding Base of Basic Science of Stomatology and Key Laboratory of Oral Biomedicine Ministry of Education, School and Hospital of Stomatology, Medical Research Institute, Wuhan University, Wuhan, China; Frontier Science Center for Immunology and Metabolism, Wuhan University, Wuhan
| | - Weidong Liu
- The State Key Laboratory Breeding Base of Basic Science of Stomatology and Key Laboratory of Oral Biomedicine Ministry of Education, School and Hospital of Stomatology, Medical Research Institute, Wuhan University, Wuhan
| | - Jin Hu
- The State Key Laboratory Breeding Base of Basic Science of Stomatology and Key Laboratory of Oral Biomedicine Ministry of Education, School and Hospital of Stomatology, Medical Research Institute, Wuhan University, Wuhan, China; Frontier Science Center for Immunology and Metabolism, Wuhan University, Wuhan
| | - Yuhua Wang
- The State Key Laboratory Breeding Base of Basic Science of Stomatology and Key Laboratory of Oral Biomedicine Ministry of Education, School and Hospital of Stomatology, Medical Research Institute, Wuhan University, Wuhan
| | - Zheming Liu
- Cancer Center, Renmin Hospital, Wuhan University, Wuhan.
| | - Haojian Zhang
- The State Key Laboratory Breeding Base of Basic Science of Stomatology and Key Laboratory of Oral Biomedicine Ministry of Education, School and Hospital of Stomatology, Medical Research Institute, Wuhan University, Wuhan, China; Frontier Science Center for Immunology and Metabolism, Wuhan University, Wuhan, China; Taikang Center for Life and Medical Sciences, Wuhan University, Wuhan, China;.
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Liu D, Xing R, Zhang Q, Tian X, Qi Y, Song H, Liu Y, Yu H, Zhang X, Jing Q, Yan C, Han Y. The CREG1-FBXO27-LAMP2 axis alleviates diabetic cardiomyopathy by promoting autophagy in cardiomyocytes. Exp Mol Med 2023; 55:2025-2038. [PMID: 37658156 PMCID: PMC10545673 DOI: 10.1038/s12276-023-01081-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2022] [Revised: 05/26/2023] [Accepted: 06/27/2023] [Indexed: 09/03/2023] Open
Abstract
Autophagy plays an important role in the development of diabetic cardiomyopathy. Cellular repressor of E1A-stimulated genes 1 (CREG1) is an important myocardial protective factor. The aim of this study was to investigate the effects and mechanisms of CREG1 in diabetic cardiomyopathy. Male C57BL/6 J mice, Creg1 transgenic mice and cardiac-specific knockout mice were used to establish a type 2 diabetes model. Small animal ultrasound, Masson's staining and western blotting were used to evaluate cardiac function, myocardial fibrosis and autophagy. Neonatal mouse cardiomyocytes (NMCMs) were stimulated with palmitate, and the effects of CREG1 on NMCMs autophagy were examined. CREG1 deficiency exacerbated cardiac dysfunction, cardiac hypertrophy and fibrosis in mice with diabetic cardiomyopathy, which was accompanied by exacerbated autophagy dysfunction. CREG1 overexpression improved cardiac function and ameliorated cardiac hypertrophy and fibrosis in diabetic cardiomyopathy by improving autophagy. CREG1 protein expression was decreased in palmitate-induced NMCMs. CREG1 knockdown exacerbated cardiomyocyte hypertrophy and inhibited autophagy. CREG1 overexpression inhibited cardiomyocyte hypertrophy and improved autophagy. LAMP2 overexpression reversed the effect of CREG1 knockdown on palmitate-induced inhibition of cardiomyocyte autophagy. CREG1 inhibited LAMP2 protein degradation by inhibiting the protein expression of F-box protein 27 (FBXO27). Our findings indicate new roles of CREG1 in the development of diabetic cardiomyopathy.
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Affiliation(s)
- Dan Liu
- State Key Laboratory of Frigid Zone Cardiovascular Diseases, Cardiovascular Research Institute and Department of Cardiology, General Hospital of Northern Theater Command, Shenyang, China
| | - Ruinan Xing
- State Key Laboratory of Frigid Zone Cardiovascular Diseases, Cardiovascular Research Institute and Department of Cardiology, General Hospital of Northern Theater Command, Shenyang, China
| | - Quanyu Zhang
- State Key Laboratory of Frigid Zone Cardiovascular Diseases, Cardiovascular Research Institute and Department of Cardiology, General Hospital of Northern Theater Command, Shenyang, China
| | - Xiaoxiang Tian
- State Key Laboratory of Frigid Zone Cardiovascular Diseases, Cardiovascular Research Institute and Department of Cardiology, General Hospital of Northern Theater Command, Shenyang, China
| | - Yanping Qi
- State Key Laboratory of Frigid Zone Cardiovascular Diseases, Cardiovascular Research Institute and Department of Cardiology, General Hospital of Northern Theater Command, Shenyang, China
| | - Haixu Song
- State Key Laboratory of Frigid Zone Cardiovascular Diseases, Cardiovascular Research Institute and Department of Cardiology, General Hospital of Northern Theater Command, Shenyang, China
| | - Yanxia Liu
- State Key Laboratory of Frigid Zone Cardiovascular Diseases, Cardiovascular Research Institute and Department of Cardiology, General Hospital of Northern Theater Command, Shenyang, China
| | - Haibo Yu
- State Key Laboratory of Frigid Zone Cardiovascular Diseases, Cardiovascular Research Institute and Department of Cardiology, General Hospital of Northern Theater Command, Shenyang, China
| | - Xiaolin Zhang
- State Key Laboratory of Frigid Zone Cardiovascular Diseases, Cardiovascular Research Institute and Department of Cardiology, General Hospital of Northern Theater Command, Shenyang, China
| | - Quanmin Jing
- State Key Laboratory of Frigid Zone Cardiovascular Diseases, Cardiovascular Research Institute and Department of Cardiology, General Hospital of Northern Theater Command, Shenyang, China
| | - Chenghui Yan
- State Key Laboratory of Frigid Zone Cardiovascular Diseases, Cardiovascular Research Institute and Department of Cardiology, General Hospital of Northern Theater Command, Shenyang, China.
| | - Yaling Han
- State Key Laboratory of Frigid Zone Cardiovascular Diseases, Cardiovascular Research Institute and Department of Cardiology, General Hospital of Northern Theater Command, Shenyang, China.
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8
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Oh J, Park C, Kim S, Kim M, Kim CS, Jo W, Park S, Yi GS, Park J. High levels of intracellular endotrophin in adipocytes mediate COPII vesicle supplies to autophagosome to impair autophagic flux and contribute to systemic insulin resistance in obesity. Metabolism 2023:155629. [PMID: 37302692 DOI: 10.1016/j.metabol.2023.155629] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/06/2023] [Revised: 05/25/2023] [Accepted: 06/08/2023] [Indexed: 06/13/2023]
Abstract
BACKGROUND AND AIMS Extracellular matrix (ECM) homeostasis plays a crucial role in metabolic plasticity and endocrine function of adipose tissue. High levels of intracellular endotrophin, a cleavage peptide of type VI collagen alpha 3 chain (Col6a3), have been frequently observed in adipocyte in obesity and diabetes. However, how endotrophin intracellularly traffics and influences metabolic homeostasis in adipocyte remains unknown. Therefore, we aimed to investigate the trafficking of endotrophin and its metabolic effects in adipocytes depending on lean or obese condition. METHODS We used doxycycline-inducible adipocyte-specific endotrophin overexpressed mice for a gain-of-function study and CRISPR-Cas9 system-based Col6a3-deficient mice for a loss-of-function study. Various molecular and biochemical techniques were employed to examine the effects of endotrophin on metabolic parameters. RESULTS In adipocytes during obesity, the majority of endosomal endotrophin escapes lysosomal degradation and is released into the cytosol to mediate direct interactions between SEC13, a major component of coat protein complex II (COPII) vesicles, and autophagy-related 7 (ATG7), leading to the increased formation of autophagosomes. Autophagosome accumulation disrupts the balance of autophagic flux, resulting in adipocyte death, inflammation, and insulin resistance. These adverse metabolic effects were ameliorated by either suppressing ATG7 with siRNA ex vivo or neutralizing endotrophin with monoclonal antibodies in vivo. CONCLUSIONS High levels of intracellular endotrophin-mediated autophagic flux impairment in adipocyte contribute to metabolic dysfunction such as apoptosis, inflammation, and insulin resistance in obesity.
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Affiliation(s)
- Jiyoung Oh
- Department of Biological Sciences, College of Information and Biotechnology, Ulsan National Institute of Science and Technology, Ulsan 44919, Republic of Korea
| | - Chanho Park
- Department of Biological Sciences, College of Information and Biotechnology, Ulsan National Institute of Science and Technology, Ulsan 44919, Republic of Korea
| | - Sahee Kim
- Department of Biological Sciences, College of Information and Biotechnology, Ulsan National Institute of Science and Technology, Ulsan 44919, Republic of Korea
| | - Min Kim
- Department of Biological Sciences, College of Information and Biotechnology, Ulsan National Institute of Science and Technology, Ulsan 44919, Republic of Korea
| | - Chu-Sook Kim
- Department of Biological Sciences, College of Information and Biotechnology, Ulsan National Institute of Science and Technology, Ulsan 44919, Republic of Korea
| | - Woobeen Jo
- Department of Biological Sciences, College of Information and Biotechnology, Ulsan National Institute of Science and Technology, Ulsan 44919, Republic of Korea
| | - Sungho Park
- Department of Biological Sciences, College of Information and Biotechnology, Ulsan National Institute of Science and Technology, Ulsan 44919, Republic of Korea
| | - Gwan-Su Yi
- Department of Bio and Brain Engineering, Korea Advanced Institute of Science and Technology, Daejeon 34141, Republic of Korea
| | - Jiyoung Park
- Department of Biological Sciences, College of Information and Biotechnology, Ulsan National Institute of Science and Technology, Ulsan 44919, Republic of Korea.
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Popli P, Tang S, Chadchan SB, Talwar C, Rucker EB, Guan X, Monsivais D, Lydon JP, Stallings CL, Moley KH, Kommagani R. Beclin-1-dependent autophagy, but not apoptosis, is critical for stem-cell-mediated endometrial programming and the establishment of pregnancy. Dev Cell 2023; 58:885-897.e4. [PMID: 37040770 PMCID: PMC10289806 DOI: 10.1016/j.devcel.2023.03.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2022] [Revised: 01/31/2023] [Accepted: 03/16/2023] [Indexed: 04/13/2023]
Abstract
The human endometrium shows a remarkable regenerative capacity that enables cyclical regeneration and remodeling throughout a woman's reproductive life. Although early postnatal uterine developmental cues direct this regeneration, the vital factors that govern early endometrial programming are largely unknown. We report that Beclin-1, an essential autophagy-associated protein, plays an integral role in uterine morphogenesis during the early postnatal period. We show that conditional depletion of Beclin-1 in the uterus triggers apoptosis and causes progressive loss of Lgr5+/Aldh1a1+ endometrial progenitor stem cells, with concomitant loss of Wnt signaling, which is crucial for stem cell renewal and epithelial gland development. Beclin-1 knockin (Becn1 KI) mice with disabled apoptosis exhibit normal uterine development. Importantly, the restoration of Beclin-1-driven autophagy, but not apoptosis, promotes normal uterine adenogenesis and morphogenesis. Together, the data suggest that Beclin-1-mediated autophagy acts as a molecular switch that governs the early uterine morphogenetic program by maintaining the endometrial progenitor stem cells.
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Affiliation(s)
- Pooja Popli
- Department of Pathology and Immunology, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030, USA
| | - Suni Tang
- Department of Pathology and Immunology, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030, USA
| | - Sangappa B Chadchan
- Department of Pathology and Immunology, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030, USA
| | - Chandni Talwar
- Department of Pathology and Immunology, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030, USA
| | - Edmund B Rucker
- Department of Biology, University of Kentucky, Lexington, KY 40506, USA
| | - Xiaoming Guan
- Department of Obstetrics and Gynecology, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030, USA
| | - Diana Monsivais
- Department of Pathology and Immunology, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030, USA
| | - John P Lydon
- Department of Molecular and Cellular Biology, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030, USA
| | - Christina L Stallings
- Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, MO 63110, USA; Center for Women's Infectious Disease Research, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Kelle H Moley
- Department Obstetrics and Gynecology, Washington University School of Medicine, St. Louis, MO 63110, USA; Center for Reproductive Health Sciences, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Ramakrishna Kommagani
- Department of Pathology and Immunology, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030, USA; Department of Molecular Virology and Microbiology, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030, USA.
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10
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Transcriptomic changes in autophagy-related genes are inversely correlated with inflammation and are associated with multiple sclerosis lesion pathology. Brain Behav Immun Health 2022; 25:100510. [PMID: 36120103 PMCID: PMC9478930 DOI: 10.1016/j.bbih.2022.100510] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2022] [Revised: 06/22/2022] [Accepted: 09/04/2022] [Indexed: 01/18/2023] Open
Abstract
Autophagy is a lysosomal degradative pathway essential for maintaining cellular homeostasis and is also implicated in multiple aspects of both innate and adaptive immunity. Neuroinflammation, along with demyelination and axonal loss, is an important component of multiple sclerosis (MS). Induction of autophagy ameliorated disease progression in experimental autoimmune encephalomyelitis (EAE), a mouse model for MS, underlying a possible link between autophagy and MS pathology. However, it is still unclear how autophagy is affected during different stages of MS. Here, we show a decreased expression of the autophagy-related (ATG) genes during the acute phase of EAE development in mice as well as in mixed active/inactive lesions of post-mortem human MS brain tissues. Using spatial transcriptomics, we observed that this decreased ATG gene expression is most prominent in the core of mixed active/inactive lesions. Furthermore, we observed a hyper-activation of the mammalian target of rapamycin complex 1 (mTORC1) in lesions, which could inhibit both the initiation of autophagy and the transcription factors that regulate the expression of the ATG genes. Thus, based on our data, we propose a negative regulation of autophagy in MS, possibly through persistent mTORC1 activation, which depends on the lesion stage. Our results contribute to the understanding of the role of autophagy in different stages of MS pathology and point to the mTORC1 pathway as a potential modulator that likely regulates central nervous system (CNS) homeostasis and neuroinflammation in MS. Autophagy is differently regulated in various EAE and MS stages. Expression of ATG genes inversely correlates with inflammation in EAE mice. ATG gene expression is decreased in mixed active/inactive brain lesions. Targeting mTORC1 may be a promising therapeutic target in MS pathology.
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11
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Systemic Beta-Hydroxybutyrate Affects BDNF and Autophagy into the Retina of Diabetic Mice. Int J Mol Sci 2022; 23:ijms231710184. [PMID: 36077579 PMCID: PMC9455989 DOI: 10.3390/ijms231710184] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2022] [Revised: 09/02/2022] [Accepted: 09/03/2022] [Indexed: 11/17/2022] Open
Abstract
Background: Diabetic retinopathy (DR) is a neurovascular disease, characterized by a deficiency of brain-derived neurotrophic factor (BDNF), a regulator of autophagy. Beta-hydroxybutyrate (BHB), previously reported as a protective agent in DR, has been associated with BDNF promotion. Here, we investigated whether systemic BHB affects the retinal levels of BDNF and local autophagy in diabetic mice with retinopathy; Methods: C57BL/6J mice were administered with intraperitoneal (i.p.) streptozotocin (STZ) (75 mg/kg) injection to develop diabetes. After 2 weeks, they received i.p. injections of BHB (25−50−100 mg/kg) twice a week for 10 weeks. Retinal samples were collected in order to perform immunofluorescence, Western blotting, and ELISA analysis; Results: BHB 50 mg/kg and 100 mg/kg significantly improved retinal BDNF levels (p < 0.01) in diabetic mice. This improvement was negatively associated with autophagosome−lysosome formations (marked by LC3B and ATG14) and to higher levels of connexin 43 (p < 0.01), a marker of cell integrity. Moreover, BHB administration significantly reduced M1 microglial activation and autophagy (p < 0.01); Conclusions: The systemic administration of BHB in mice with DR improves the retinal levels of BDNF, with the consequent reduction of the abnormal microglial autophagy. This leads to retinal cell safety through connexin 43 restoration.
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12
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Morawe MP, Liao F, Amberg W, van Bergeijk J, Chang R, Gulino M, Hamilton C, Hoft C, Lumpkin C, Mastis B, McGlame E, Nuber J, Plaas C, Ravikumar B, Roy K, Schanzenbächer M, Tierno J, Lakics V, Dellovade T, Townsend M. Pharmacological mTOR-inhibition facilitates clearance of AD-related tau aggregates in the mouse brain. Eur J Pharmacol 2022; 934:175301. [DOI: 10.1016/j.ejphar.2022.175301] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2022] [Revised: 09/20/2022] [Accepted: 09/22/2022] [Indexed: 11/03/2022]
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13
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Budi YP, Li YH, Huang C, Wang ME, Lin YC, Jong DS, Chiu CH, Jiang YF. The role of autophagy in high-fat diet-induced insulin resistance of adipose tissues in mice. PeerJ 2022; 10:e13867. [PMID: 35990905 PMCID: PMC9387522 DOI: 10.7717/peerj.13867] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2022] [Accepted: 07/19/2022] [Indexed: 01/18/2023] Open
Abstract
Aims Studies have observed changes in autophagic flux in the adipose tissue of type 2 diabetes patients with obesity. However, the role of autophagy in obesity-induced insulin resistance is unclear. We propose to confirm the effect of a high-fat diet (HFD) on autophagy and insulin signaling transduction from adipose tissue to clarify whether altered autophagy-mediated HFD induces insulin resistance, and to elucidate the possible mechanisms in autophagy-regulated adipose insulin sensitivity. Methods Eight-week-old male C57BL/6 mice were fed with HFD to confirm the effect of HFD on autophagy and insulin signaling transduction from adipose tissue. Differentiated 3T3-L1 adipocytes were treated with 1.2 mM fatty acids (FAs) and 50 nM Bafilomycin A1 to determine the autophagic flux. 2.5 mg/kg body weight dose of Chloroquine (CQ) in PBS was locally injected into mouse epididymal adipose (10 and 24 h) and 40 µM of CQ to 3T3-L1 adipocytes for 24 h to evaluate the role of autophagy in insulin signaling transduction. Results The HFD treatment resulted in a significant increase in SQSTM1/p62, Rubicon expression, and C/EBP homologous protein (CHOP) expression, yet the insulin capability to induce Akt (Ser473) and GSK3β (Ser9) phosphorylation were reduced. PHLPP1 and PTEN remain unchanged after CQ injection. In differentiated 3T3-L1 adipocytes treated with CQ, although the amount of phospho-Akt stimulated by insulin in the CQ-treated group was significantly lower, CHOP expressions and cleaved caspase-3 were increased and bafilomycin A1 induced less accumulation of LC3-II protein. Conclusion Long-term high-fat diet promotes insulin resistance, late-stage autophagy inhibition, ER stress, and apoptosis in adipose tissue. Autophagy suppression may not affect insulin signaling transduction via phosphatase expression but indirectly causes insulin resistance through ER stress or apoptosis.
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Affiliation(s)
- Yovita Permata Budi
- Graduate Institute of Molecular and Comparative Pathobiology, National Taiwan University, Taipei, Taiwan,School of Veterinary Medicine, National Taiwan University, Taipei, Taiwan
| | - Yi-Hsuan Li
- Department of Animal Science and Technology, National Taiwan University, Taipei, Taiwan
| | - Chien Huang
- Department of Animal Science and Technology, National Taiwan University, Taipei, Taiwan
| | - Mu-En Wang
- Department of Pathology, Duke University, North Carolina, Durham, United States of America
| | - Yi-Chun Lin
- Department of Animal Science, National Chung Hsing University, Taichung, Taichung, Taiwan
| | - De-Shien Jong
- Department of Animal Science and Technology, National Taiwan University, Taipei, Taiwan
| | - Chih-Hsien Chiu
- Department of Animal Science and Technology, National Taiwan University, Taipei, Taiwan
| | - Yi-Fan Jiang
- Graduate Institute of Molecular and Comparative Pathobiology, National Taiwan University, Taipei, Taiwan,School of Veterinary Medicine, National Taiwan University, Taipei, Taiwan
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14
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Cangelosi AL, Puszynska AM, Roberts JM, Armani A, Nguyen TP, Spinelli JB, Kunchok T, Wang B, Chan SH, Lewis CA, Comb WC, Bell GW, Helman A, Sabatini DM. Zonated leucine sensing by Sestrin-mTORC1 in the liver controls the response to dietary leucine. Science 2022; 377:47-56. [PMID: 35771919 PMCID: PMC10049859 DOI: 10.1126/science.abi9547] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
The mechanistic target of rapamycin complex 1 (mTORC1) kinase controls growth in response to nutrients, including the amino acid leucine. In cultured cells, mTORC1 senses leucine through the leucine-binding Sestrin proteins, but the physiological functions and distribution of Sestrin-mediated leucine sensing in mammals are unknown. We find that mice lacking Sestrin1 and Sestrin2 cannot inhibit mTORC1 upon dietary leucine deprivation and suffer a rapid loss of white adipose tissue (WAT) and muscle. The WAT loss is driven by aberrant mTORC1 activity and fibroblast growth factor 21 (FGF21) production in the liver. Sestrin expression in the liver lobule is zonated, accounting for zone-specific regulation of mTORC1 activity and FGF21 induction by leucine. These results establish the mammalian Sestrins as physiological leucine sensors and reveal a spatial organization to nutrient sensing by the mTORC1 pathway.
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Affiliation(s)
- Andrew L. Cangelosi
- Whitehead Institute for Biomedical Research, Cambridge, MA 02142, USA
- Howard Hughes Medical Institute, Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Anna M. Puszynska
- Whitehead Institute for Biomedical Research, Cambridge, MA 02142, USA
- Howard Hughes Medical Institute, Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Justin M. Roberts
- Whitehead Institute for Biomedical Research, Cambridge, MA 02142, USA
- Howard Hughes Medical Institute, Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Andrea Armani
- Whitehead Institute for Biomedical Research, Cambridge, MA 02142, USA
- Howard Hughes Medical Institute, Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
- Veneto Institute of Molecular Medicine, 35129 Padova, Italy
- Department of Biomedical Sciences, University of Padova, 35131 Padova, Italy
| | - Thao P. Nguyen
- Whitehead Institute for Biomedical Research, Cambridge, MA 02142, USA
- Howard Hughes Medical Institute, Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Jessica B. Spinelli
- Whitehead Institute for Biomedical Research, Cambridge, MA 02142, USA
- Howard Hughes Medical Institute, Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Tenzin Kunchok
- Whitehead Institute for Biomedical Research, Cambridge, MA 02142, USA
| | - Brianna Wang
- Whitehead Institute for Biomedical Research, Cambridge, MA 02142, USA
| | - Sze Ham Chan
- Whitehead Institute for Biomedical Research, Cambridge, MA 02142, USA
| | - Caroline A. Lewis
- Whitehead Institute for Biomedical Research, Cambridge, MA 02142, USA
| | - William C. Comb
- Whitehead Institute for Biomedical Research, Cambridge, MA 02142, USA
- Howard Hughes Medical Institute, Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - George W. Bell
- Whitehead Institute for Biomedical Research, Cambridge, MA 02142, USA
| | - Aharon Helman
- Institute of Biochemistry, Food Science and Nutrition, Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot 7610001, Israel
| | - David M. Sabatini
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
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15
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Quantitative phosphoproteomic analyses identify STK11IP as a lysosome-specific substrate of mTORC1 that regulates lysosomal acidification. Nat Commun 2022; 13:1760. [PMID: 35365663 PMCID: PMC8976005 DOI: 10.1038/s41467-022-29461-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2021] [Accepted: 03/14/2022] [Indexed: 01/02/2023] Open
Abstract
The evolutionarily conserved serine/threonine kinase mTORC1 is a central regulator of cell growth and proliferation. mTORC1 is activated on the lysosome surface. However, once mTORC1 is activated, it is unclear whether mTORC1 phosphorylates local lysosomal proteins to regulate specific aspects of lysosomal biology. Through cross-reference analyses of the lysosome proteome with the mTORC1-regulated phosphoproteome, we identify STK11IP as a lysosome-specific substrate of mTORC1. mTORC1 phosphorylates STK11IP at Ser404. Knockout of STK11IP leads to a robust increase of autophagy flux. Dephosphorylation of STK11IP at Ser404 represses the role of STK11IP as an autophagy inhibitor. Mechanistically, STK11IP binds to V-ATPase, and regulates the activity of V-ATPase. Knockout of STK11IP protects mice from fasting or Methionine/Choline-Deficient Diet (MCD)-induced fatty liver. Thus, our study demonstrates that STK11IP phosphorylation represents a mechanism for mTORC1 to regulate lysosomal acidification and autophagy, and points to STK11IP as a promising therapeutic target for the amelioration of diseases with aberrant autophagy signaling.
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16
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Zhang Z, Li H, Su Y, Ma J, Yuan Y, Yu Z, Shi M, Shao S, Zhang Z, Hölscher C. Neuroprotective Effects of a Cholecystokinin Analogue in the 1-Methyl-4-Phenyl-1,2,3,6-Tetrahydropyridine Parkinson’s Disease Mouse Model. Front Neurosci 2022; 16:814430. [PMID: 35368248 PMCID: PMC8964967 DOI: 10.3389/fnins.2022.814430] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2021] [Accepted: 02/11/2022] [Indexed: 01/13/2023] Open
Abstract
Parkinson’s disease (PD) is a chronic neurodegenerative disease. Type 2 diabetes mellitus (T2DM) has been identified as a risk factor for PD. Drugs originally developed for T2DM treatment such as liraglutide have shown neuroprotective effects in mouse models of PD. Cholecystokinin (CCK) is a peptide hormone with growth factor properties. Here, we demonstrate the neuroprotective effects of the (pGLu)-(Gln)-CCK8 analogue in an acute PD mouse model induced by 1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP). Administration of CCK analogue (50 nmol/kg ip.) for 14 days treatment improved the locomotor and exploratory activity of mice, and improved bradykinesia and movement balance of mice. The CCK analogue administration also restored tyrosine hydroxylase (TH) positive dopaminergic neurons number and synapse number (synaptophysin levels) in the substantia nigra pars compacta (SNpc). The CCK analogue decreased glia activation and neuroinflammation in the SNpc, and regulated autophagy dysfunction induced by MPTP. CCK analogue protected against mitochondrial damage and ER stress, and also decreased the ratio of apoptosis signaling molecules Bax/Bcl-2. Importantly, the CCK analogue improved the decrease of p-CREBS133 growth factor signaling in the SNpc. Therefore, the CCK analogue promotes cell survival of dopaminergic neuron in the SNpc by activating the cAMP/PKA/CREB pathway that also inhibits apoptosis and regulates autophagy impairment. The present results indicate that CCK analogue shows a promising potential for the treatment of PD.
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Affiliation(s)
- Zijuan Zhang
- Academy of Chinese Medical Sciences, Henan University of Chinese Medicine, Zhengzhou, China
- School of Medical Sciences, Henan University of Chinese Medicine, Zhengzhou, China
| | - Hai Li
- Academy of Chinese Medical Sciences, Henan University of Chinese Medicine, Zhengzhou, China
- School of Medical Sciences, Henan University of Chinese Medicine, Zhengzhou, China
| | - Yunfang Su
- Academy of Chinese Medical Sciences, Henan University of Chinese Medicine, Zhengzhou, China
| | - Jinlian Ma
- Academy of Chinese Medical Sciences, Henan University of Chinese Medicine, Zhengzhou, China
| | - Ye Yuan
- Academy of Chinese Medical Sciences, Henan University of Chinese Medicine, Zhengzhou, China
| | - Ziyang Yu
- School of Medical Sciences, Henan University of Chinese Medicine, Zhengzhou, China
| | - Ming Shi
- School of Medical Sciences, Henan University of Chinese Medicine, Zhengzhou, China
| | - Simai Shao
- School of Medical Sciences, Henan University of Chinese Medicine, Zhengzhou, China
| | - Zhenqiang Zhang
- Academy of Chinese Medical Sciences, Henan University of Chinese Medicine, Zhengzhou, China
- Zhenqiang Zhang,
| | - Christian Hölscher
- Academy of Chinese Medical Sciences, Henan University of Chinese Medicine, Zhengzhou, China
- Neurology Department of the Second Associated Hospital of Shanxi Medical University, Taiyuan, China
- *Correspondence: Christian Hölscher,
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17
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Zhao QX, Wang YH, Wang SC, Xue S, Cao ZX, Sun T. Protectin DX Attenuates Lumbar Radicular Pain of Non-compressive Disc Herniation by Autophagy Flux Stimulation via Adenosine Monophosphate-Activated Protein Kinase Signaling. Front Physiol 2022; 12:784653. [PMID: 35069245 PMCID: PMC8770935 DOI: 10.3389/fphys.2021.784653] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2021] [Accepted: 12/08/2021] [Indexed: 11/13/2022] Open
Abstract
Background: Neuroinflammation plays a crucial role in initiating and sustaining lumbar radicular pain (LRP). Protectin DX (PDX) has been experimentally verified to possess pro-resolving properties and anti-inflammatory effects. This study aimed to observe the analgesic effects of PDX and its potential mechanisms in LRP rats with non-compressive lumbar disc herniation (NCLDH). Method: Only male rats were selected to avoid gender-related interferences. Rat models of NCLDH were established, and rats were randomly divided into four groups: the sham group, the vehicle group, the PDX (10 ng PDX) group, and the PDX (100 ng PDX) group. Changes in the mechanical withdrawal threshold and thermal withdrawal latency were observed for 7 days. The mRNAs of pro-inflammatory and anti-inflammatory mediators were evaluated via real-time polymerase chain reaction, whereas western blot and immunohistochemistry were separately conducted to assess the expression levels of autophagy-related proteins and adenosine monophosphate-activated protein kinase (AMPK) signaling. Results: Intrathecal delivery of PDX reduced interleukin (IL)-6 and IL-1β mRNA levels and facilitated mRNA transcription of transforming growth factor-β1, with attenuation of mechanical and thermal hyperalgesia in LRP rat models. With the application of nucleus pulposus to the dorsal root ganglion, autophagy flux and AMPK signaling were severely disrupted in the spinal dorsal horns, and intrathecal treatment with PDX could dose-dependently restore the dysfunction of autophagy flux and AMPK signaling. Conclusion: These data suggest that PDX possesses pro-resolving properties and exerts potent analgesic effects in LRP by affecting autophagy flux via AMPK signaling.
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Affiliation(s)
- Qing-Xiang Zhao
- Department of Pain Management, Shandong Provincial Hospital, Cheeloo College of Medicine, Shandong University, Jinan, China.,Department of Pain Management, Binzhou Medical University Hospital, Binzhou, China
| | - Yi-Hao Wang
- Department of Pain Management, Shandong Provincial Hospital, Cheeloo College of Medicine, Shandong University, Jinan, China
| | - Si-Cong Wang
- Departments of Pain Management, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, China
| | - Song Xue
- Department of Pain Management, Shandong Provincial Hospital, Cheeloo College of Medicine, Shandong University, Jinan, China
| | - Zhen-Xin Cao
- Departments of Pain Management, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, China
| | - Tao Sun
- Department of Pain Management, Shandong Provincial Hospital, Cheeloo College of Medicine, Shandong University, Jinan, China.,Departments of Pain Management, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, China
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18
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Sipos F, Bohusné Barta B, Simon Á, Nagy L, Dankó T, Raffay RE, Petővári G, Zsiros V, Wichmann B, Sebestyén A, Műzes G. Survival of HT29 Cancer Cells Is Affected by IGF1R Inhibition via Modulation of Self-DNA-Triggered TLR9 Signaling and the Autophagy Response. Pathol Oncol Res 2022; 28:1610322. [PMID: 35651701 PMCID: PMC9148969 DOI: 10.3389/pore.2022.1610322] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/17/2022] [Accepted: 04/27/2022] [Indexed: 02/05/2023]
Abstract
Purpose: In HT29 colon cancer cells, a close interplay between self-DNA-induced TLR9 signaling and autophagy response was found, with remarkable effects on cell survival and differentiation. IGF1R activation drives the development and malignant progression of colorectal cancer. IGF1R inhibition displays a controversial effect on autophagy. The interrelated roles of IGF1R inhibition and TLR9/autophagy signaling in HT29 cancer cells have not yet been clarified. In our study, we aimed to investigate the complex interplay of IGF1R inhibition and TLR9/autophagy signaling in HT29 cells. Methods: HT29 cells were incubated with tumor-originated self-DNA with or without inhibitors of IGF1R (picropodophyllin), autophagy (chloroquine), and TLR9 (ODN2088), respectively. Cell proliferation and metabolic activity measurements, direct cell counting, NanoString and Taqman gene expression analyses, immunocytochemistry, WES Simple Western blot, and transmission electron microscopy investigations were performed. Results: The concomitant use of tumor-derived self-DNA and IGF1R inhibitors displays anti-proliferative potential, which can be reversed by parallel TLR9 signaling inhibition. The distinct effects of picropodophyllin, ODN2088, and chloroquine per se or in combination on HT29 cell proliferation and autophagy suggest that either the IGF1R-associated or non-associated autophagy machinery is "Janus-faced" regarding its actions on cell proliferation. Autophagy, induced by different combinations of self-DNA and inhibitors is not sufficient to rescue HT29 cells from death but results in the survival of some CD133-positive stem-like HT29 cells. Conclusion: The creation of new types of combined IGF1R, autophagy, and/or TLR9 signaling inhibitors would play a significant role in the development of more personalized anti-tumor therapies for colorectal cancer.
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Affiliation(s)
- Ferenc Sipos
- Department of Internal Medicine and Hematology, Semmelweis University, Budapest, Hungary
- *Correspondence: Ferenc Sipos,
| | - Bettina Bohusné Barta
- Department of Internal Medicine and Hematology, Semmelweis University, Budapest, Hungary
| | - Ágnes Simon
- Department of Internal Medicine and Hematology, Semmelweis University, Budapest, Hungary
| | - Lőrinc Nagy
- Department of Internal Medicine and Hematology, Semmelweis University, Budapest, Hungary
| | - Titanilla Dankó
- Department of Pathology and Experimental Cancer Research, Semmelweis University, Budapest, Hungary
| | - Regina Eszter Raffay
- Department of Pathology and Experimental Cancer Research, Semmelweis University, Budapest, Hungary
| | - Gábor Petővári
- Department of Pathology and Experimental Cancer Research, Semmelweis University, Budapest, Hungary
| | - Viktória Zsiros
- Department of Anatomy, Histology and Embryology, Semmelweis University, Budapest, Hungary
| | | | - Anna Sebestyén
- Department of Pathology and Experimental Cancer Research, Semmelweis University, Budapest, Hungary
| | - Györgyi Műzes
- Department of Internal Medicine and Hematology, Semmelweis University, Budapest, Hungary
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19
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Abstract
Autophagy is an evolutionarily conserved, lysosome-dependent catabolic process whereby cytoplasmic components, including damaged organelles, protein aggregates and lipid droplets, are degraded and their components recycled. Autophagy has an essential role in maintaining cellular homeostasis in response to intracellular stress; however, the efficiency of autophagy declines with age and overnutrition can interfere with the autophagic process. Therefore, conditions such as sarcopenic obesity, insulin resistance and type 2 diabetes mellitus (T2DM) that are characterized by metabolic derangement and intracellular stresses (including oxidative stress, inflammation and endoplasmic reticulum stress) also involve the accumulation of damaged cellular components. These conditions are prevalent in ageing populations. For example, sarcopenia is an age-related loss of skeletal muscle mass and strength that is involved in the pathogenesis of both insulin resistance and T2DM, particularly in elderly people. Impairment of autophagy results in further aggravation of diabetes-related metabolic derangements in insulin target tissues, including the liver, skeletal muscle and adipose tissue, as well as in pancreatic β-cells. This Review summarizes the role of autophagy in the pathogenesis of metabolic diseases associated with or occurring in the context of ageing, including insulin resistance, T2DM and sarcopenic obesity, and describes its potential as a therapeutic target.
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Affiliation(s)
- Munehiro Kitada
- Department of Diabetology and Endocrinology, Kanazawa Medical University, Uchinada, Ishikawa, Japan
- Division of Anticipatory Molecular Food Science and Technology, Medical Research Institute, Kanazawa Medical University, Uchinada, Ishikawa, Japan
| | - Daisuke Koya
- Department of Diabetology and Endocrinology, Kanazawa Medical University, Uchinada, Ishikawa, Japan.
- Division of Anticipatory Molecular Food Science and Technology, Medical Research Institute, Kanazawa Medical University, Uchinada, Ishikawa, Japan.
- Department of General Internal Medicine, Kusatsu General Hospital, Kusatsu, Shiga, Japan.
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20
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Involvement of Autophagy in Ageing and Chronic Cholestatic Diseases. Cells 2021; 10:cells10102772. [PMID: 34685751 PMCID: PMC8534511 DOI: 10.3390/cells10102772] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Revised: 10/05/2021] [Accepted: 10/13/2021] [Indexed: 01/18/2023] Open
Abstract
Autophagy is a “housekeeping” lysosomal degradation process involved in numerous physiological and pathological processes in all eukaryotic cells. The dysregulation of hepatic autophagy has been described in several conditions, from obesity to diabetes and cholestatic disease. We review the role of autophagy, focusing on age-related cholestatic diseases, and discuss its therapeutic potential and the molecular targets identified to date. The accumulation of toxic BAs is the main cause of cell damage in cholestasis patients. BAs and their receptor, FXR, have been implicated in the regulation of hepatic autophagy. The mechanisms by which cholestasis induces liver damage include mitochondrial dysfunction, oxidative stress and ER stress, which lead to cell death and ultimately to liver fibrosis as a compensatory mechanism to reduce the damage. The stimulation of autophagy seems to ameliorate the liver damage. Autophagic activity decreases with age in several species, whereas its basic extends lifespan in animals, suggesting that it is one of the convergent mechanisms of several longevity pathways. No strategies aimed at inducing autophagy have yet been tested in cholestasis patients. However, its stimulation can be viewed as a novel therapeutic strategy that may reduce ageing-dependent liver deterioration and also mitigate hepatic steatosis.
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Leduc-Gaudet JP, Hussain SNA, Barreiro E, Gouspillou G. Mitochondrial Dynamics and Mitophagy in Skeletal Muscle Health and Aging. Int J Mol Sci 2021; 22:ijms22158179. [PMID: 34360946 PMCID: PMC8348122 DOI: 10.3390/ijms22158179] [Citation(s) in RCA: 96] [Impact Index Per Article: 32.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2021] [Revised: 07/23/2021] [Accepted: 07/27/2021] [Indexed: 01/18/2023] Open
Abstract
The maintenance of mitochondrial integrity is critical for muscle health. Mitochondria, indeed, play vital roles in a wide range of cellular processes, including energy supply, Ca2+ homeostasis, retrograde signaling, cell death, and many others. All mitochondria-containing cells, including skeletal muscle cells, dispose of several pathways to maintain mitochondrial health, including mitochondrial biogenesis, mitochondrial-derived vesicles, mitochondrial dynamics (fusion and fission process shaping mitochondrial morphology), and mitophagy—the process in charge of the removal of mitochondria though autophagy. The loss of skeletal muscle mass (atrophy) is a major health problem worldwide, especially in older people. Currently, there is no treatment to counteract the progressive decline in skeletal muscle mass and strength that occurs with aging, a process termed sarcopenia. There is increasing data, including our own, suggesting that accumulation of dysfunctional mitochondria contributes to the development of sarcopenia. Impairments in mitochondrial dynamics and mitophagy were recently proposed to contribute to sarcopenia. This review summarizes the current state of knowledge on the role played by mitochondrial dynamics and mitophagy in skeletal muscle health and in the development of sarcopenia. We also highlight recent studies showing that enhancing mitophagy in skeletal muscle is a promising therapeutic target to prevent or even treat skeletal muscle dysfunction in the elderly.
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Affiliation(s)
- Jean-Philippe Leduc-Gaudet
- Research Institute of the McGill University Health Centre, Department of Critical Care, Montréal, QC H4A 3J1, Canada; (S.N.A.H.); (G.G.)
- Meakins-Christie Laboratories, Department of Medicine, McGill University, Montréal, QC H4A 3J1, Canada
- Département des Sciences de l’activité Physique, Faculté des Sciences, UQAM, Montréal, QC H2X 1Y4, Canada
- Correspondence: ; Tel.: +1-514-476-6688
| | - Sabah N. A. Hussain
- Research Institute of the McGill University Health Centre, Department of Critical Care, Montréal, QC H4A 3J1, Canada; (S.N.A.H.); (G.G.)
- Meakins-Christie Laboratories, Department of Medicine, McGill University, Montréal, QC H4A 3J1, Canada
| | - Esther Barreiro
- Pulmonology Department-Muscle Wasting & Cachexia in Chronic Respiratory Diseases & Lung Cancer Research Group, IMIM-Hospital del Mar, Parc de Salut Mar, Biomedical Research Park (PRBB), C/Dr. Aiguader, 88, 08003 Barcelona, Spain;
- Centro de Investigación en Red de Enfermedades Respiratorias (CIBERES), Instituto de Salud Carlos III (ISCIII), 28029 Madrid, Spain
- Health and Experimental Sciences Department (CEXS), Pompeu Fabra University (UPF), Biomedical Research Park (PRBB), C/Dr. Aiguader, 88, 08003 Barcelona, Spain
| | - Gilles Gouspillou
- Research Institute of the McGill University Health Centre, Department of Critical Care, Montréal, QC H4A 3J1, Canada; (S.N.A.H.); (G.G.)
- Meakins-Christie Laboratories, Department of Medicine, McGill University, Montréal, QC H4A 3J1, Canada
- Département des Sciences de l’activité Physique, Faculté des Sciences, UQAM, Montréal, QC H2X 1Y4, Canada
- Centre de Recherche de l’Institut Universitaire de Gériatrie de Montréal, Montréal, QC H3W 1W5, Canada
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Xu ZQ, Zhang JJ, Kong N, Zhang GY, Ke P, Han T, Su DF, Liu C. Autophagy is Involved in Neuroprotective Effect of Alpha7 Nicotinic Acetylcholine Receptor on Ischemic Stroke. Front Pharmacol 2021; 12:676589. [PMID: 33995108 PMCID: PMC8117007 DOI: 10.3389/fphar.2021.676589] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2021] [Accepted: 04/14/2021] [Indexed: 01/14/2023] Open
Abstract
The α7 nicotinic acetylcholine receptor (α7nAChR) belongs to the superfamily of cys loop cationic ligand-gated channels, which consists of homogeneous α7 subunits. Although our lab found that activation of α7nAChR could alleviate ischemic stroke, the mechanism is still unknown. Herein, we explored whether autophagy is involved in the neuroprotective effect mediated by α7nAChR in ischemic stroke. Transient middle cerebral artery occlusion (tMCAO) and oxygen and glucose deprivation (OGD/R) exposure were applied to in vivo and in vitro models of ischemic stroke, respectively. Neurological deficit score and infarct volume were used to evaluate outcomes of tMCAO in the in vivo study. Autophagy-related proteins were detected by Western blot, and autophagy flux was detected by using tandem fluorescent mRFP-GFP-LC3 lentivirus. At 24 h after tMCAO, α7nAChR knockout mice showed worse neurological function and larger infarct volume than wild-type mice. PNU282987, an α7nAChR agonist, protected against OGD/R-induced neuronal injury, enhanced autophagy, and promoted autophagy flux. However, the beneficial effects of PNU282987 were eliminated by 3-methyladenine (3-MA), an autophagy inhibitor. Moreover, we found that PNU282987 treatment could activate the AMPK-mTOR-p70S6K signaling pathway in the in vitro study, while the effect was attenuated by compound C, an AMPK inhibitor. Our results demonstrated that the beneficial effect on neuronal survival via activation of α7nAChR was associated with enhanced autophagy, and the AMPK-mTOR-p70S6K signaling pathway was involved in α7nAChR activation-mediated neuroprotection.
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Affiliation(s)
- Zhe-Qi Xu
- Department of Pharmacy, Second Military Medical University, Shanghai, China
| | - Jing-Jing Zhang
- Department of Pharmacy, Second Military Medical University, Shanghai, China
| | - Ni Kong
- Department of Pharmacy, Second Military Medical University, Shanghai, China
| | - Guang-Yu Zhang
- Department of Pharmacy, Second Military Medical University, Shanghai, China
| | - Ping Ke
- Department of Pharmacy, Second Military Medical University, Shanghai, China
| | - Ting Han
- Department of Pharmacy, Second Military Medical University, Shanghai, China
| | - Ding-Feng Su
- Department of Pharmacy, Second Military Medical University, Shanghai, China
| | - Chong Liu
- Department of Pharmacy, Second Military Medical University, Shanghai, China
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Guo X, Li Q, Xiang J, Liu M, Guan A, Tang Y, Sun H. A hybrid aggregate FRET probe from the mixed assembly of cyanine dyes for highly specific monitoring of mitochondria autophagy. Anal Chim Acta 2021; 1165:338561. [PMID: 33975703 DOI: 10.1016/j.aca.2021.338561] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2021] [Revised: 03/27/2021] [Accepted: 04/19/2021] [Indexed: 10/21/2022]
Abstract
Mitochondria autophagy, also known as mitophagy, is a process in which mitochondria are wrapped by autophagosomes and fused with lysosomes for degradation. This process is essential for mitochondrial quality control. Here, we developed a hybrid aggregate FRET probe through mixed assembly of two cyanine dyes FMOTY and AMTC. In live cells, FMOTY and AMTC exist independently in lysosomes and mitochondria and will not produce interfering FRET background signals. The FRET signal is only generated when mitochondria is transported to lysosomes during mitophagy. This allows the hybridized aggregate to be used as a highly specific probe for monitoring mitophagy.
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Affiliation(s)
- Xiaomeng Guo
- Beijing National Laboratory for Molecular Sciences (BNLMS), State Key Laboratory for Structural Chemistry of Unstable and Stable Species, Institute of Chemistry Chinese Academy of Sciences, Beijing, 100190, PR China; University of Chinese Academy of Sciences, Beijing, 100049, PR China
| | - Qian Li
- Center for Physicochemical Analysis and Measurement, Institute of Chemistry Chinese Academy of Sciences, Beijing, 100190, PR China
| | - Junfeng Xiang
- Center for Physicochemical Analysis and Measurement, Institute of Chemistry Chinese Academy of Sciences, Beijing, 100190, PR China
| | - Meirong Liu
- Center for Physicochemical Analysis and Measurement, Institute of Chemistry Chinese Academy of Sciences, Beijing, 100190, PR China
| | - Aijiao Guan
- Beijing National Laboratory for Molecular Sciences (BNLMS), State Key Laboratory for Structural Chemistry of Unstable and Stable Species, Institute of Chemistry Chinese Academy of Sciences, Beijing, 100190, PR China
| | - Yalin Tang
- Beijing National Laboratory for Molecular Sciences (BNLMS), State Key Laboratory for Structural Chemistry of Unstable and Stable Species, Institute of Chemistry Chinese Academy of Sciences, Beijing, 100190, PR China; University of Chinese Academy of Sciences, Beijing, 100049, PR China
| | - Hongxia Sun
- Beijing National Laboratory for Molecular Sciences (BNLMS), State Key Laboratory for Structural Chemistry of Unstable and Stable Species, Institute of Chemistry Chinese Academy of Sciences, Beijing, 100190, PR China.
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Kim HY, Nam SY, Kim HM, Jeong HJ. Exposure of ovalbumin during pregnancy prevents the development of allergic rhinitis in offspring through the induction of mast cell autophagy. Cell Immunol 2021; 365:104362. [PMID: 33905950 DOI: 10.1016/j.cellimm.2021.104362] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2020] [Revised: 04/09/2021] [Accepted: 04/12/2021] [Indexed: 10/21/2022]
Abstract
Most allergic disease studies have focused on postnatal chemical or microbial exposure. Recent studies have indicated that allergic diseases are associated with the immunological interaction between the mother and her offspring, but the relevant mechanisms are unclear. The aim of this study was to assess whether maternal exposure to allergens during pregnancy could affect allergic rhinitis (AR) in the offspring. Compared with offspring of naïve mothers, offspring of ovalbumin (OVA)-exposed mothers exhibited a significant reduction in AR clinical symptoms and levels of histamine, IgE, T helper type-2(Th2) cytokines, thymic stromal lymphopoietin, cyclooxygenase-2, chemokines, infiltration of inflammatory cell, and activity of caspase-1. Interestingly, we observed that offspring of OVA-exposed mothers regulated OVA-induced Th2 responses by inducing autophagy in mast cells. Our data demonstrated that maternal exposure to OVA during pregnancy decreased allergic sensitivity in offspring, suggesting that the vertical transmission of maternal immune responses may be involved. These findings have important implications in the regulation of AR. Furthermore, we propose that the autophagy of mast cells may be a potential target for AR prevention or treatment.
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Affiliation(s)
- Hee-Yun Kim
- Biochip Research Center, Hoseo University, Asan, Chungnam 31499, Republic of Korea
| | - Sun-Young Nam
- Department of Pharmacology, College of Korean Medicine, Kyung Hee University, Seoul 02447, Republic of Korea
| | - Hyung-Min Kim
- Department of Pharmacology, College of Korean Medicine, Kyung Hee University, Seoul 02447, Republic of Korea
| | - Hyun-Ja Jeong
- Biochip Research Center, Hoseo University, Asan, Chungnam 31499, Republic of Korea; Department of Food Science & Technology, Hoseo University, Asan 31499, Republic of Korea.
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25
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Zhang LL, Zhang XY, Lu YY, Bi YD, Liu XL, Fang F. The Role of Autophagy in Murine Cytomegalovirus Hepatitis. Viral Immunol 2021; 34:241-255. [PMID: 33566740 DOI: 10.1089/vim.2020.0024] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Autophagy is involved in the pathogenesis of multiple pathogen infection. Previous studies have reported that human cytomegalovirus (CMV) activates autophagy in the early stage of infection and then inhibits autophagy. Little is known about the role of autophagy in murine CMV (MCMV) infection, especially in MCMV-induced hepatitis. The purpose of this study is to investigate the role of autophagy in MCMV hepatitis. BALB/c mice were infected with MCMV and a series of experiments involving western blot, immunofluorescence, immunohistochemistry, H&E (Hematoxylin and Eosin) staining and quantitative real-time polymerase chain reaction were performed in this study. The expression of SQSTM1/p62, PI3K, the ratio of phosphorylated Akt to total Akt, and the ratio of phosphorylated mammalian target of rapamycin (mTOR) to total mTOR were increased, and the expression of light-chain 3 (LC3)-II were decreased in the livers of infected mice on days 3 and 7 postinfection (p.i.). Compared with the untreated infected group, increased transcription level of MCMV glycoprotein B (gB), increased expression levels of interleukin1-β (IL-1β), aspartate aminotransferase (AST) and alanine aminotransferase (ALT), decreased expression level of type I interferon α (IFN-α), as well as aggravated liver pathological injury were detected in starvation-treated infected group on days 3 and 7 p.i.; whereas decreased transcription level of MCMV gB, decreased expression levels of IL-1β, AST and ALT, increased expression level of type I IFN-α, as well as alleviated liver pathological injury were detected in chloroquine (CQ)-treated infected group on day 3 p.i. In conclusion, autophagy is inhibited through activating the PI3K/Akt/mTOR pathway in the liver of BALB/c mice during MCMV infection, and autophagy may promote MCMV replication and aggravate liver pathological damage and inflammation. Further understanding of the interactions between autophagy and MCMV infection and its potential mechanism may bring new important cues to the control of MCMV infection and antiviral therapy.
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Affiliation(s)
- Lin-Lin Zhang
- Department of Pediatrics, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Xin-Yan Zhang
- Department of Pediatrics, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Yuan-Yuan Lu
- Department of Pediatrics, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Yi-Dan Bi
- Department of Pediatrics, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Xing-Lou Liu
- Department of Pediatrics, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Feng Fang
- Department of Pediatrics, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
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Fourrier C, Bryksin V, Hattersley K, Hein LK, Bensalem J, Sargeant TJ. Comparison of chloroquine-like molecules for lysosomal inhibition and measurement of autophagic flux in the brain. Biochem Biophys Res Commun 2021; 534:107-113. [PMID: 33316543 DOI: 10.1016/j.bbrc.2020.12.008] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2020] [Accepted: 12/01/2020] [Indexed: 12/11/2022]
Abstract
Measurement of autophagic flux in vivo is critical to understand how autophagy can be used to combat disease. Neurodegenerative diseases have a special relationship with autophagy, which makes measurement of autophagy in the brain a significant research priority. Currently, measurement of autophagic flux is possible through use of transgenic constructs, or application of a lysosomal inhibitor such as chloroquine. Unfortunately, chloroquine is not useful for measuring autophagic flux in the brain and the use of transgenic animals necessitates cross-breeding of transgenic strains and maintenance of lines, which is costly. To find a drug that could block lysosomal function in the brain for the measurement of autophagic flux, we selected compounds from the literature that appeared to have similar properties to chloroquine and tested their ability to inhibit autophagic flux in cell culture and in mice. These chemicals included chloroquine, quinacrine, mefloquine, promazine and trifluoperazine. As expected, chloroquine blocked lysosomal degradation of the autophagic protein LC3B-II in cell culture. Quinacrine also inhibited autophagic flux in cell culture. Other compounds tested were not effective. When injected into mice, chloroquine caused accumulation of LC3B-II in heart tissue, and quinacrine was effective at blocking LC3B-II degradation in male, but not female skeletal muscle. None of the compounds tested were useful for measuring autophagic flux in the brain. During this study we also noted that the vehicle DMSO powerfully up-regulated LC3B-II abundance in tissues. This study shows that chloroquine and quinacrine can both be used to measure autophagic flux in cells, and in some peripheral tissues. However, measurement of flux in the brain using lysosomal inhibitors remains an unresolved research challenge.
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Affiliation(s)
- Célia Fourrier
- Lysosomal Health in Ageing, Lifelong Health Theme, South Australian Health and Medical Research Institute, PO Box 11060, Adelaide, 5001, South Australia, Australia.
| | - Valerie Bryksin
- Lysosomal Health in Ageing, Lifelong Health Theme, South Australian Health and Medical Research Institute, PO Box 11060, Adelaide, 5001, South Australia, Australia.
| | - Kathryn Hattersley
- Lysosomal Health in Ageing, Lifelong Health Theme, South Australian Health and Medical Research Institute, PO Box 11060, Adelaide, 5001, South Australia, Australia.
| | - Leanne K Hein
- Lysosomal Health in Ageing, Lifelong Health Theme, South Australian Health and Medical Research Institute, PO Box 11060, Adelaide, 5001, South Australia, Australia.
| | - Julien Bensalem
- Lysosomal Health in Ageing, Lifelong Health Theme, South Australian Health and Medical Research Institute, PO Box 11060, Adelaide, 5001, South Australia, Australia.
| | - Timothy J Sargeant
- Lysosomal Health in Ageing, Lifelong Health Theme, South Australian Health and Medical Research Institute, PO Box 11060, Adelaide, 5001, South Australia, Australia.
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Bosch M, Parton RG, Pol A. Lipid droplets, bioenergetic fluxes, and metabolic flexibility. Semin Cell Dev Biol 2020; 108:33-46. [DOI: 10.1016/j.semcdb.2020.02.010] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2019] [Revised: 02/13/2020] [Accepted: 02/27/2020] [Indexed: 12/18/2022]
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Abstract
Endosomal microautophagy (eMI) is a type of autophagy that allows for the selective uptake and degradation of cytosolic proteins in late endosome/multi-vesicular bodies (LE/MVB). This process starts with the recognition of a pentapeptide amino acid KFERQ-like targeting motif in the substrate protein by the hsc70 chaperone, which then enables binding and subsequent uptake of the protein into the LE/MVB compartment. The recognition of a KFERQ-like motif by hsc70 is the same initial step in chaperone-mediated autophagy (CMA), a form of selective autophagy that degrades the hsc70-targeted proteins in lysosomes in a LAMP-2A dependent manner. The shared step of substrate recognition by hsc70, originally identified for CMA, makes it now necessary to differentiate between the two pathways. Here, we detail biochemical and imaging-based methods to track eMI activity in vitro with isolated LE/MVBs and in cells in culture using fluorescent reporters and highlight approaches to distinguish whether a protein is a substrate of eMI or CMA.
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Affiliation(s)
- Gregory J Krause
- Department of Developmental and Molecular Biology, Albert Einstein College of Medicine, New York, NY, United States; Institute for Aging Studies, Albert Einstein College of Medicine, New York, NY, United States
| | - Ana Maria Cuervo
- Department of Developmental and Molecular Biology, Albert Einstein College of Medicine, New York, NY, United States; Institute for Aging Studies, Albert Einstein College of Medicine, New York, NY, United States.
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O-GlcNAcylation Is Essential for Autophagy in Cardiomyocytes. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2020; 2020:5602396. [PMID: 32850000 PMCID: PMC7439163 DOI: 10.1155/2020/5602396] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/04/2020] [Revised: 06/21/2020] [Accepted: 07/27/2020] [Indexed: 12/20/2022]
Abstract
Since both O-GlcNAcylation and autophagy sense intracellular nutrient level, the alteration of those two pathways plays substantial roles in the progression of heart failure. Hence, determining the relationship between O-GlcNAcylation and autophagy is imperative to understand, prevent, and treat heart failure. However, the mechanism on how O-GlcNAcylation regulates autophagy in the heart is poorly investigated. In this study, we demonstrated that O-GlcNAcylation is required for autophagy in cardiomyocytes by utilizing an O-linked β-N-acetylglucosamine transferase (OGT) cardiomyocyte-specific knockout mouse model for the first time. We also identified that OGT might regulate the initiation of autophagy in cardiomyocytes through promoting the activity of ULK1 by O-GlcNAcylation. In conclusion, our findings provide new insights into the molecular mechanisms underlying heart dysfunction and benefit the development of treatments for heart failure.
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Combination therapy with TiO 2 nanoparticles and cisplatin enhances chemotherapy response in murine melanoma models. Clin Transl Oncol 2020; 23:738-749. [PMID: 32734535 DOI: 10.1007/s12094-020-02463-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2020] [Accepted: 07/17/2020] [Indexed: 10/23/2022]
Abstract
BACKGROUND Despite recent progressions in the treatment of melanoma, the response to conventional therapies and the long-term survival in melanoma patients still remain poor. Recently, the use of nanoparticles (NPs) has been highlighted for promoting the chemotherapeutic effects of cytotoxic drugs in melanoma. The aim of this study is to mechanistically evaluate the potential of titanium dioxide (TiO2) nanoparticles (NPs) for enhancing chemotherapy effects in in vitro and in vivo models of murine melanoma. METHODS The F10 melanoma cells were exposed to different concentrations of TiO2 NPs and/or cisplatin, then cell growth, cell viability, and cell death were evaluated. In parallel, C57BL/6 syngeneic melanoma mice were treated by TiO2 NPs and/or cisplatin, and then drug responses, tumor size and mice's organs were studied pathologically. Autophagy was examined by evaluating the formation of autophagosomes and gene expression levels of autophagy markers (ATG5 and ATG6) by fluorescent microscopy and qPCR, respectively. RESULTS Nontoxic concentrations of TiO2 NPs (50 µg/ml) promote anti-proliferative and cytotoxic effects of cisplatin in F10 melanoma cells, which is mediated through the induction of autophagy and necrotic cell death. Whereas TiO2 NPs have no cytotoxic or metastatic effects in melanoma mice, its combination with cisplatin enhances drug responses (up to 50%), leading to higher inhibition of tumor growth compared with each monotherapy. CONCLUSION The combination of TiO2 NP with cisplatin enhances chemotherapy response in both in vitro and in vivo melanoma models. In addition, autophagy plays an essential role during sensitizing melanoma cells to chemotherapy.
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Di Pardo A, Pepe G, Capocci L, Marracino F, Amico E, Del Vecchio L, Giova S, Jeong SK, Park BM, Park BD, Maglione V. Treatment with K6PC-5, a selective stimulator of SPHK1, ameliorates intestinal homeostasis in an animal model of Huntington's disease. Neurobiol Dis 2020; 143:105009. [PMID: 32634578 DOI: 10.1016/j.nbd.2020.105009] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2020] [Revised: 06/10/2020] [Accepted: 06/29/2020] [Indexed: 02/08/2023] Open
Abstract
Emerging evidence indicates that Huntington's disease (HD) may be described as multi-organ pathology. In this context, we and others have contributed to demonstrate that the disease is characterized by an impairment of the homeostasis of gastro-intestinal (GI) tract. Sphingolipids represent a class of molecules involved in the regulation and maintenance of different tissues and organs including GI system. In this study, we investigated whether the alteration of Sphingosine-1-phosphate (S1P) metabolism, previously described in human HD brains and animal models, is also detectable peripherally in R6/2 HD mice. Our findings indicate, for the first time, that sphingolipid metabolism is perturbed early in the disease in the intestinal tract of HD mice and, its modulation by K6PC-5, a selective activator of S1P synthesis, preserved intestinal integrity and homeostasis. These results further support the evidence that modulation of sphingolipid pathways may represent a potential therapeutic option in HD and suggest that it has also the potential to counteract the peripheral disturbances which may usually complicate the management of the disease and affect patient's quality of life.
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Affiliation(s)
| | - G Pepe
- IRCCS Neuromed, Pozzilli, Italy
| | | | | | - E Amico
- IRCCS Neuromed, Pozzilli, Italy
| | - L Del Vecchio
- IRCCS Neuromed, Pozzilli, Italy; Unità complessa di radiodiagnostica (U.O.C.) POS, University of Foggia, Foggia, Italy
| | - S Giova
- IRCCS Neuromed, Pozzilli, Italy
| | - S K Jeong
- Department of Cosmetic Science, Seowon University, Cheongju, Republic of Korea
| | - B M Park
- NeoPharm USA Inc., Engelwood Cliffs, NJ, USA
| | - B D Park
- Dr. Raymond Laboratories, Inc, Englewood cliffs, NJ, USA
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Oliva Trejo JA, Tanida I, Suzuki C, Kakuta S, Tada N, Uchiyama Y. Characterization of starvation-induced autophagy in cerebellar Purkinje cells of pHluorin-mKate2-human LC3B transgenic mice. Sci Rep 2020; 10:9643. [PMID: 32541814 PMCID: PMC7295967 DOI: 10.1038/s41598-020-66370-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2019] [Accepted: 05/19/2020] [Indexed: 12/25/2022] Open
Abstract
We generated a new transgenic mouse model that expresses a pHluorin-mKate2 fluorescent protein fused with human LC3B (PK-LC3 mice) for monitoring autophagy activity in neurons of the central nervous system. Histological analysis revealed fluorescent puncta in neurons of the cerebral cortex, hippocampus, cerebellar Purkinje cells, and anterior spinal regions. Using CLEM analysis, we confirmed that PK-LC3-positive puncta in the perikarya of Purkinje cells correspond to autophagic structures. To validate the usability of PK-LC3 mice, we quantified PK-LC3 puncta in Purkinje cells of mice kept in normal feeding conditions and of mice starved for 24 hours. Our results showed a significant increase in autophagosome number and in individual puncta areal size following starvation. To confirm these results, we used morphometry at the electron microscopic level to analyze the volume densities of autophagosomes and lysosomes/autolysosomes in Purkinje cells of PK-LC3 mice. The results revealed that the volume densities of autophagic structures increase significantly after starvation. Together, our data show that PK-LC3 mice are suitable for monitoring autophagy flux in Purkinje cells of the cerebellum, and potentially other areas in the central nervous system.
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Affiliation(s)
- Juan Alejandro Oliva Trejo
- Department of Cellular and Molecular Neuropathology, Juntendo University Graduate School of Medicine, Bunkyo-Ku, Tokyo, Japan
| | - Isei Tanida
- Department of Cellular and Molecular Neuropathology, Juntendo University Graduate School of Medicine, Bunkyo-Ku, Tokyo, Japan.
| | - Chigure Suzuki
- Department of Cellular and Molecular Neuropathology, Juntendo University Graduate School of Medicine, Bunkyo-Ku, Tokyo, Japan
| | - Soichiro Kakuta
- Department of Cellular and Molecular Neuropathology, Juntendo University Graduate School of Medicine, Bunkyo-Ku, Tokyo, Japan
| | - Norihiro Tada
- Research Institute for Diseases of Old Age, Juntendo University School of Medicine, Bunkyo-Ku, Tokyo, Japan
| | - Yasuo Uchiyama
- Department of Cellular and Molecular Neuropathology, Juntendo University Graduate School of Medicine, Bunkyo-Ku, Tokyo, Japan.
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Ochaba J, Powers AF, Tremble KA, Greenlee S, Post NM, Matson JE, MacLeod AR, Guo S, Aghajan M. A novel and translational role for autophagy in antisense oligonucleotide trafficking and activity. Nucleic Acids Res 2020; 47:11284-11303. [PMID: 31612951 PMCID: PMC6868497 DOI: 10.1093/nar/gkz901] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2019] [Revised: 09/13/2019] [Accepted: 10/01/2019] [Indexed: 01/26/2023] Open
Abstract
Endocytosis is a mechanism by which cells sense their environment and internalize various nutrients, growth factors and signaling molecules. This process initiates at the plasma membrane, converges with autophagy, and terminates at the lysosome. It is well-established that cellular uptake of antisense oligonucleotides (ASOs) proceeds through the endocytic pathway; however, only a small fraction escapes endosomal trafficking while the majority are rendered inactive in the lysosome. Since these pathways converge and share common molecular machinery, it is unclear if autophagy-related trafficking participates in ASO uptake or whether modulation of autophagy affects ASO activity and localization. To address these questions, we investigated the effects of autophagy modulation on ASO activity in cells and mice. We found that enhancing autophagy through small-molecule mTOR inhibition, serum-starvation/fasting, and ketogenic diet, increased ASO-mediated target reduction in vitro and in vivo. Additionally, autophagy activation enhanced the localization of ASOs into autophagosomes without altering intracellular concentrations or trafficking to other compartments. These results support a novel role for autophagy and the autophagosome as a previously unidentified compartment that participates in and contributes to enhanced ASO activity. Further, we demonstrate non-chemical methods to enhance autophagy and subsequent ASO activity using translatable approaches such as fasting or ketogenic diet.
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Affiliation(s)
- Joseph Ochaba
- Ionis Pharmaceuticals, Inc., Carlsbad, CA 92010, USA
| | | | | | | | - Noah M Post
- Ionis Pharmaceuticals, Inc., Carlsbad, CA 92010, USA
| | - John E Matson
- Ionis Pharmaceuticals, Inc., Carlsbad, CA 92010, USA
| | | | - Shuling Guo
- Ionis Pharmaceuticals, Inc., Carlsbad, CA 92010, USA
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34
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Bonam SR, Bayry J, Tschan MP, Muller S. Progress and Challenges in The Use of MAP1LC3 as a Legitimate Marker for Measuring Dynamic Autophagy In Vivo. Cells 2020; 9:E1321. [PMID: 32466347 PMCID: PMC7291013 DOI: 10.3390/cells9051321] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2020] [Revised: 05/20/2020] [Accepted: 05/21/2020] [Indexed: 01/02/2023] Open
Abstract
Tremendous efforts have been made these last decades to increase our knowledge of intracellular degradative systems, especially in the field of autophagy. The role of autophagy in the maintenance of cell homeostasis is well documented and the existence of defects in the autophagic machinery has been largely described in diseases and aging. Determining the alterations occurring in the many forms of autophagy that coexist in cells and tissues remains complicated, as this cellular process is highly dynamic in nature and can vary from organ to organ in the same individual. Although autophagy is extensively studied, its functioning in different tissues and its links with other biological processes is still poorly understood. Several assays have been developed to monitor autophagy activity in vitro, ex vivo, and in vivo, based on different markers, the use of various inhibitors and activators, and distinct techniques. This review emphasizes the methods applied to measure (macro-)autophagy in tissue samples and in vivo via a protein, which centrally intervenes in the autophagy pathway, the microtubule-associated protein 1A/1B-light chain 3 (MAP1LC3), which is the most widely used marker and the first identified to associate with autophagosomal structures. These approaches are presented and discussed in terms of pros and cons. Some recommendations are provided to improve the reliability of the interpretation of results.
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Affiliation(s)
- Srinivasa Reddy Bonam
- CNRS, Biotechnology and Cell Signaling, Ecole Supérieure de Biotechnologie de Strasbourg, Illkirch, 67412 Strasbourg University/Laboratory of Excellence Medalis, 67000 Strasbourg, France
- Institut National de la Santé et de la Recherche Médicale, Centre de Recherche des Cordeliers, Sorbonne Université, Université de Paris, 75006 Paris, France;
| | - Jagadeesh Bayry
- Institut National de la Santé et de la Recherche Médicale, Centre de Recherche des Cordeliers, Sorbonne Université, Université de Paris, 75006 Paris, France;
| | - Mario P. Tschan
- Institute of Pathology, Division of Experimental Pathology, University of Bern, 3008 Bern, Switzerland;
| | - Sylviane Muller
- CNRS, Biotechnology and Cell Signaling, Ecole Supérieure de Biotechnologie de Strasbourg, Illkirch, 67412 Strasbourg University/Laboratory of Excellence Medalis, 67000 Strasbourg, France
- Fédération Hospitalo-Universitaire OMICARE, Fédération de Médecine Translationnelle de Strasbourg, Strasbourg University, 67000 Strasbourg, France
- University of Strasbourg Institute for Advanced Study, 67000 Strasbourg, France
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35
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Neill T, Chen CG, Buraschi S, Iozzo RV. Catabolic degradation of endothelial VEGFA via autophagy. J Biol Chem 2020; 295:6064-6079. [PMID: 32209654 DOI: 10.1074/jbc.ra120.012593] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2020] [Revised: 03/19/2020] [Indexed: 01/04/2023] Open
Abstract
Extracellular matrix-evoked angiostasis and autophagy within the tumor microenvironment represent two critical, but unconnected, functions of the small leucine-rich proteoglycan, decorin. Acting as a partial agonist of vascular endothelial growth factor 2 (VEGFR2), soluble decorin signals via the energy sensing protein, AMP-activated protein kinase (AMPK), in the autophagic degradation of intracellular vascular endothelial growth factor A (VEGFA). Here, we discovered that soluble decorin evokes intracellular catabolism of endothelial VEGFA that is mechanistically independent of mTOR, but requires an autophagic regulator, paternally expressed gene 3 (PEG3). We found that administration of autophagic inhibitors such as chloroquine or bafilomycin A1, or depletion of autophagy-related 5 (ATG5), results in accumulation of intracellular VEGFA, indicating that VEGFA is a basal autophagic substrate. Mechanistically, decorin increased the VEGFA clearance rate by augmenting autophagic flux, a process that required RAB24 member RAS oncogene family (RAB24), a small GTPase that facilitates the disposal of autophagic compartments. We validated these findings by demonstrating the physiological relevance of this process in vivo Mice starved for 48 h exhibited a sharp decrease in overall cardiac and aortic VEGFA that could be blocked by systemic chloroquine treatment. Thus, our findings reveal a unified mechanism for the metabolic control of endothelial VEGFA for autophagic clearance in response to decorin and canonical pro-autophagic stimuli. We posit that the VEGFR2/AMPK/PEG3 axis integrates the anti-angiogenic and pro-autophagic bioactivities of decorin as the molecular basis for tumorigenic suppression. These results support future therapeutic use of decorin as a next-generation protein therapy to combat cancer.
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Affiliation(s)
- Thomas Neill
- Department of Pathology, Anatomy, and Cell Biology, and the Cancer Cell Biology and Signaling Program, Sidney Kimmel Medical College at Thomas Jefferson University, Philadelphia, Pennsylvania 19107.
| | - Carolyn G Chen
- Department of Pathology, Anatomy, and Cell Biology, and the Cancer Cell Biology and Signaling Program, Sidney Kimmel Medical College at Thomas Jefferson University, Philadelphia, Pennsylvania 19107
| | - Simone Buraschi
- Department of Pathology, Anatomy, and Cell Biology, and the Cancer Cell Biology and Signaling Program, Sidney Kimmel Medical College at Thomas Jefferson University, Philadelphia, Pennsylvania 19107
| | - Renato V Iozzo
- Department of Pathology, Anatomy, and Cell Biology, and the Cancer Cell Biology and Signaling Program, Sidney Kimmel Medical College at Thomas Jefferson University, Philadelphia, Pennsylvania 19107.
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36
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Long Term Pharmacological Perturbation of Autophagy in Mice: Are HCQ Injections a Relevant Choice? Biomedicines 2020; 8:biomedicines8030047. [PMID: 32121613 PMCID: PMC7148514 DOI: 10.3390/biomedicines8030047] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2020] [Revised: 02/27/2020] [Accepted: 02/27/2020] [Indexed: 12/13/2022] Open
Abstract
Macroautophagy (hereafter referred to as autophagy) is an evolutionarily conserved catabolic process whose loss-of-function has been linked to a growing list of pathologies. Knockout mouse models of key autophagy genes have been instrumental in the demonstration of the critical functions of autophagy, but they display early lethality, neurotoxicity and unwanted autophagy-independent phenotypes, limiting their applications for in vivo studies. To avoid problems encountered with autophagy-null transgenic mice, we investigated the possibility of disturbing autophagy pharmacologically in the long term. Hydroxychloroquine (HCQ) ip injections were done in juvenile and adult C57bl/6j mice, at range doses adapted from the human malaria prophylactic treatment. The impact on autophagy was assessed by western-blotting, and juvenile neurodevelopment and adult behaviours were evaluated for four months. Quite surprisingly, our results showed that HCQ treatment in conditions used in this study neither impacted autophagy in the long term in several tissues and organs nor altered neurodevelopment, adult behaviour and motor capabilities. Therefore, we recommend for future long-term in vivo studies of autophagy, to use genetic mouse models allowing conditional inhibition of selected Atg genes in appropriate lineage cells instead of HCQ treatment, until it could be successfully revisited using higher HCQ doses and/or frequencies with acceptable toxicity.
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Marsh T, Kenific CM, Suresh D, Gonzalez H, Shamir ER, Mei W, Tankka A, Leidal AM, Kalavacherla S, Woo K, Werb Z, Debnath J. Autophagic Degradation of NBR1 Restricts Metastatic Outgrowth during Mammary Tumor Progression. Dev Cell 2020; 52:591-604.e6. [PMID: 32084360 DOI: 10.1016/j.devcel.2020.01.025] [Citation(s) in RCA: 66] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2019] [Revised: 11/25/2019] [Accepted: 01/22/2020] [Indexed: 01/06/2023]
Abstract
Although autophagy is being pursued as a therapeutic target in clinical oncology trials, its effects on metastasis, the principal cause of cancer mortality, remain unclear. Here, we utilize mammary cancer models to temporally delete essential autophagy regulators during carcinoma progression. Though genetic ablation of autophagy strongly attenuates primary mammary tumor growth, impaired autophagy promotes spontaneous metastasis and enables the outgrowth of disseminated tumor cells into overt macro-metastases. Transcriptomic analysis reveals that autophagy deficiency elicits a subpopulation of otherwise luminal tumor cells exhibiting basal differentiation traits, which is reversed upon preventing accumulation of the autophagy cargo receptor, Neighbor to BRCA1 (NBR1). Furthermore, pharmacological and genetic induction of autophagy suppresses pro-metastatic differentiation and metastatic outgrowth. Analysis of human breast cancer data reveal that autophagy gene expression inversely correlates with pro-metastatic differentiation signatures and predicts overall and distant metastasis-free survival. Overall, these findings highlight autophagy-dependent control of NBR1 as a key determinant of metastatic progression.
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Affiliation(s)
- Timothy Marsh
- Department of Pathology, University of California, San Francisco, San Francisco, CA 94143, USA; Helen Diller Family Comprehensive Cancer Center, University of California, San Francisco, San Francisco, CA 94158, USA; Biomedical Sciences Graduate program, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Candia M Kenific
- Department of Pathology, University of California, San Francisco, San Francisco, CA 94143, USA; Helen Diller Family Comprehensive Cancer Center, University of California, San Francisco, San Francisco, CA 94158, USA; Biomedical Sciences Graduate program, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Deepthisri Suresh
- Department of Pathology, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Hugo Gonzalez
- Department of Anatomy, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Eliah R Shamir
- Department of Pathology, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Wenbin Mei
- Department of Anatomy, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Alexandra Tankka
- Department of Pathology, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Andrew M Leidal
- Department of Pathology, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Sandhya Kalavacherla
- Department of Anatomy, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Kimberly Woo
- Department of Pathology, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Zena Werb
- Helen Diller Family Comprehensive Cancer Center, University of California, San Francisco, San Francisco, CA 94158, USA; Biomedical Sciences Graduate program, University of California, San Francisco, San Francisco, CA 94143, USA; Department of Anatomy, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Jayanta Debnath
- Department of Pathology, University of California, San Francisco, San Francisco, CA 94143, USA; Helen Diller Family Comprehensive Cancer Center, University of California, San Francisco, San Francisco, CA 94158, USA.
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38
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Nosaka N, Martinon D, Moreira D, Crother TR, Arditi M, Shimada K. Autophagy Protects Against Developing Increased Lung Permeability and Hypoxemia by Down Regulating Inflammasome Activity and IL-1β in LPS Plus Mechanical Ventilation-Induced Acute Lung Injury. Front Immunol 2020; 11:207. [PMID: 32117318 PMCID: PMC7033480 DOI: 10.3389/fimmu.2020.00207] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2019] [Accepted: 01/27/2020] [Indexed: 01/04/2023] Open
Abstract
Targeting inflammasome activation to modulate interleukin (IL)-1β is a promising treatment strategy against acute respiratory distress syndrome and ventilator-induced lung injury (VILI). Autophagy is a key regulator of inflammasome activation in macrophages. Here, we investigated the role of autophagy in the development of acute lung injury (ALI) induced by lipopolysaccharide (LPS) and mechanical ventilation (MV). Two hours before starting MV, 0.2 mg/kg LPS was administered to mice intratracheally. Mice were then placed on high-volume MV (30 ml/kg with 3 cmH2O positive end-expiratory pressure for 2.5 h without additional oxygen application). Mice with myeloid-specific deletion of the autophagic protein ATG16L1 (Atg16l1fl/flLysMCre) suffered severe hypoxemia (adjusted p < 0.05) and increased lung permeability (p < 0.05, albumin level in bronchoalveolar lavage fluid) with significantly higher IL-1β release into alveolar space (p < 0.05). Induction of autophagy by fasting-induced starvation led to improved arterial oxygenation (adjusted p < 0.0001) and lung permeability (p < 0.05), as well as significantly suppressed IL-1β production (p < 0.01). Intratracheal treatment with anti-mouse IL-1β monoclonal antibody (mAb; 2.5 mg/kg) significantly improved arterial oxygenation (adjusted p < 0.01) as well as lung permeability (p < 0.05). On the other hand, deletion of IL-1α gene or use of anti-mouse IL-1α mAb (2.5 mg/kg) provided no significant protection, suggesting that the LPS and MV-induced ALI is primarily dependent on IL-1β, but independent of IL-1α. These observations suggest that autophagy has a protective role in controlling inflammasome activation and production of IL-1β, which plays a critical role in developing hypoxemia and increased lung permeability in LPS plus MV-induced acute lung injury.
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Affiliation(s)
- Nobuyuki Nosaka
- Division of Infectious Diseases and Immunology, Department of Pediatrics, Cedars-Sinai Medical Center, Los Angeles, CA, United States
| | - Daisy Martinon
- Division of Infectious Diseases and Immunology, Department of Pediatrics, Cedars-Sinai Medical Center, Los Angeles, CA, United States
| | - Debbie Moreira
- Division of Infectious Diseases and Immunology, Department of Pediatrics, Cedars-Sinai Medical Center, Los Angeles, CA, United States
| | - Timothy R Crother
- Division of Infectious Diseases and Immunology, Department of Pediatrics, Cedars-Sinai Medical Center, Los Angeles, CA, United States.,Department of Biomedical Sciences, Cedars-Sinai Medical Center, Los Angeles, CA, United States
| | - Moshe Arditi
- Division of Infectious Diseases and Immunology, Department of Pediatrics, Cedars-Sinai Medical Center, Los Angeles, CA, United States.,Department of Biomedical Sciences, Cedars-Sinai Medical Center, Los Angeles, CA, United States
| | - Kenichi Shimada
- Division of Infectious Diseases and Immunology, Department of Pediatrics, Cedars-Sinai Medical Center, Los Angeles, CA, United States.,Department of Biomedical Sciences, Cedars-Sinai Medical Center, Los Angeles, CA, United States
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39
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Agrotis A, Ketteler R. On ATG4B as Drug Target for Treatment of Solid Tumours-The Knowns and the Unknowns. Cells 2019; 9:cells9010053. [PMID: 31878323 PMCID: PMC7016753 DOI: 10.3390/cells9010053] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2019] [Revised: 12/17/2019] [Accepted: 12/19/2019] [Indexed: 12/13/2022] Open
Abstract
Autophagy is an evolutionary conserved stress survival pathway that has been shown to play an important role in the initiation, progression, and metastasis of multiple cancers; however, little progress has been made to date in translation of basic research to clinical application. This is partially due to an incomplete understanding of the role of autophagy in the different stages of cancer, and also to an incomplete assessment of potential drug targets in the autophagy pathway. While drug discovery efforts are on-going to target enzymes involved in the initiation phase of the autophagosome, e.g., unc51-like autophagy activating kinase (ULK)1/2, vacuolar protein sorting 34 (Vps34), and autophagy-related (ATG)7, we propose that the cysteine protease ATG4B is a bona fide drug target for the development of anti-cancer treatments. In this review, we highlight some of the recent advances in our understanding of the role of ATG4B in autophagy and its relevance to cancer, and perform a critical evaluation of ATG4B as a druggable cancer target.
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40
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Babuta M, Furi I, Bala S, Bukong TN, Lowe P, Catalano D, Calenda C, Kodys K, Szabo G. Dysregulated Autophagy and Lysosome Function Are Linked to Exosome Production by Micro-RNA 155 in Alcoholic Liver Disease. Hepatology 2019; 70:2123-2141. [PMID: 31090940 PMCID: PMC7453183 DOI: 10.1002/hep.30766] [Citation(s) in RCA: 93] [Impact Index Per Article: 18.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/30/2018] [Accepted: 05/07/2019] [Indexed: 12/17/2022]
Abstract
Cellular homeostais, that is normally maintained through autophagy, is disrupted in alcoholic liver disease (ALD). Because autophagy and exosome biogenesis share common elements, we hypothesized that increased exosome production in ALD may be linked to disruption of autophagic function. We found impaired autophagy both in ALD and alcoholic hepatitis (AH) mouse models and human livers with ALD as indicated by increased hepatic p62 and LC3-II levels. Alcohol reduced autophagy flux in vivo in chloroquine-treated mice as well as in vitro in hepatocytes and macrophages treated with bafilomycin A. Our results revealed that alcohol targets multiple steps in the autophagy pathway. Alcohol-related decrease in mechanistic target of rapamycin (mTOR) and Ras homolog enriched in brain (Rheb), that initiate autophagy, correlated with increased Beclin1 and autophagy-related protein 7 (Atg7), proteins involved in phagophore-autophagosome formation, in ALD. We found that alcohol disrupted autophagy function at the lysosomal level through decreased lysosomal-associated membrane protein 1 (LAMP1) and lysosomal-associated membrane protein 2 (LAMP2) in livers with ALD. We identified that micro-RNA 155 (miR-155), that is increased by alcohol, targets mTOR, Rheb, LAMP1, and LAMP2 in the authophagy pathway. Consistent with this, miR-155-deficient mice were protected from alcohol-induced disruption of autophagy and showed attenuated exosome production. Mechanistically, down-regulation of LAMP1 or LAMP2 increased exosome release in hepatocytes and macrophages in the presence and absence of alcohol. These results suggested that the alcohol-induced increase in exosome production was linked to disruption of autophagy and impaired autophagosome and lysosome function. Conclusion: Alcohol affects multiple genes in the autophagy pathway and impairs autophagic flux at the lysosome level in ALD. Inhibition of LAMP1 and LAMP2 promotes exosome release in ALD. We identified miR-155 as a mediator of alcohol-related regulation of autophagy and exosome production in hepatocytes and macrophages.
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Affiliation(s)
- Mrigya Babuta
- Department of Medicine, University of Massachusetts Medical School, Worcester, MA
| | - Istvan Furi
- Department of Medicine, University of Massachusetts Medical School, Worcester, MA
| | - Shashi Bala
- Department of Medicine, University of Massachusetts Medical School, Worcester, MA
| | - Terence N Bukong
- Department of Medicine, University of Massachusetts Medical School, Worcester, MA
| | - Patrick Lowe
- Department of Medicine, University of Massachusetts Medical School, Worcester, MA
| | - Donna Catalano
- Department of Medicine, University of Massachusetts Medical School, Worcester, MA
| | - Charles Calenda
- Department of Medicine, University of Massachusetts Medical School, Worcester, MA
| | - Karen Kodys
- Department of Medicine, University of Massachusetts Medical School, Worcester, MA
| | - Gyongyi Szabo
- Department of Medicine, University of Massachusetts Medical School, Worcester, MA
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41
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Cruces-Sande M, Arcones AC, Vila-Bedmar R, Val-Blasco A, Sharabi K, Díaz-Rodríguez D, Puigserver P, Mayor F, Murga C. Autophagy mediates hepatic GRK2 degradation to facilitate glucagon-induced metabolic adaptation to fasting. FASEB J 2019; 34:399-409. [PMID: 31914606 DOI: 10.1096/fj.201901444r] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2019] [Revised: 10/07/2019] [Accepted: 10/21/2019] [Indexed: 12/13/2022]
Abstract
The liver plays a key role during fasting to maintain energy homeostasis and euglycemia via metabolic processes mainly orchestrated by the insulin/glucagon ratio. We report here that fasting or calorie restriction protocols in C57BL6 mice promote a marked decrease in the hepatic protein levels of G protein-coupled receptor kinase 2 (GRK2), an important negative modulator of both G protein-coupled receptors (GPCRs) and insulin signaling. Such downregulation of GRK2 levels is liver-specific and can be rapidly reversed by refeeding. We find that autophagy, and not the proteasome, represents the main mechanism implicated in fasting-induced GRK2 degradation in the liver in vivo. Reducing GRK2 levels in murine primary hepatocytes facilitates glucagon-induced glucose production and enhances the expression of the key gluconeogenic enzyme Pck1. Conversely, preventing full downregulation of hepatic GRK2 during fasting using adenovirus-driven overexpression of this kinase in the liver leads to glycogen accumulation, decreased glycemia, and hampered glucagon-induced gluconeogenesis, thus preventing a proper and complete adaptation to nutrient deprivation. Overall, our data indicate that physiological fasting-induced downregulation of GRK2 in the liver is key for allowing complete glucagon-mediated responses and efficient metabolic adaptation to fasting in vivo.
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Affiliation(s)
- Marta Cruces-Sande
- Departamento de Biología Molecular, Centro de Biología Molecular Severo Ochoa (UAM-CSIC), Madrid, Spain.,Instituto de Investigación Sanitaria La Princesa, Madrid, Spain.,CIBER de Enfermedades Cardiovasculares (CIBERCV), ISCIII, Madrid, Spain
| | - Alba C Arcones
- Departamento de Biología Molecular, Centro de Biología Molecular Severo Ochoa (UAM-CSIC), Madrid, Spain.,Instituto de Investigación Sanitaria La Princesa, Madrid, Spain.,CIBER de Enfermedades Cardiovasculares (CIBERCV), ISCIII, Madrid, Spain
| | - Rocío Vila-Bedmar
- Departamento de ciencias básicas de la salud, área de Bioquímica y Biología Molecular, URJC, Madrid, Spain
| | - Almudena Val-Blasco
- Departamento de Biología Molecular, Centro de Biología Molecular Severo Ochoa (UAM-CSIC), Madrid, Spain.,Instituto de Investigación Sanitaria La Princesa, Madrid, Spain.,CIBER de Enfermedades Cardiovasculares (CIBERCV), ISCIII, Madrid, Spain
| | - Kfir Sharabi
- Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, MA, USA.,Department of Cell Biology, Harvard Medical School, Boston, MA, USA
| | - Daniel Díaz-Rodríguez
- Departamento de Biología Molecular, Centro de Biología Molecular Severo Ochoa (UAM-CSIC), Madrid, Spain
| | - Pere Puigserver
- Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, MA, USA.,Department of Cell Biology, Harvard Medical School, Boston, MA, USA
| | - Federico Mayor
- Departamento de Biología Molecular, Centro de Biología Molecular Severo Ochoa (UAM-CSIC), Madrid, Spain.,Instituto de Investigación Sanitaria La Princesa, Madrid, Spain.,CIBER de Enfermedades Cardiovasculares (CIBERCV), ISCIII, Madrid, Spain
| | - Cristina Murga
- Departamento de Biología Molecular, Centro de Biología Molecular Severo Ochoa (UAM-CSIC), Madrid, Spain.,Instituto de Investigación Sanitaria La Princesa, Madrid, Spain.,CIBER de Enfermedades Cardiovasculares (CIBERCV), ISCIII, Madrid, Spain
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42
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König J, Grune T, Ott C. Assessing autophagy in murine skeletal muscle: current findings to modulate and quantify the autophagic flux. Curr Opin Clin Nutr Metab Care 2019; 22:355-362. [PMID: 31145123 DOI: 10.1097/mco.0000000000000579] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
PURPOSE OF REVIEW In addition to the currently available lysosomotropic drugs and autophagy whole-body knockout mouse models, we provide alternative methods that enable the modulation and detection of autophagic flux in vivo, discussing advantages and disadvantages of each method. RECENT FINDINGS With the autophagosome-lysosome fusion inhibitor colchicine in skeletal muscle and temporal downregulation of autophagy using a novel Autophagy related 5-short hairpin RNA (Atg5-shRNA) mouse model we mention two models that directly modulate autophagy flux in vivo. Furthermore, methods to quantify autophagy flux, such as mitophagy transgenic reporters, in situ immunofluorescent staining and multispectral imaging flow cytometry, in mature skeletal muscle and cells are addressed. SUMMARY To achieve clinical benefit, less toxic, temporary and cell-type-specific modulation of autophagy should be pursued further. A temporary knockdown as described for the Atg5-shRNA mice could provide a first insight into possible implications of autophagy inhibition. However, it is also important to take a closer look into the methods to evaluate autophagy after harvesting the tissue. In particular caution is required when experimental conditions can influence the final measurement and this should be pretested carefully.
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Affiliation(s)
- Jeannette König
- Department of Molecular Toxicology, German Institute of Human Nutrition Potsdam-Rehbruecke (DIfE), Nuthetal
- German Center for Diabetes Research (DZD), Munich
| | - Tilman Grune
- Department of Molecular Toxicology, German Institute of Human Nutrition Potsdam-Rehbruecke (DIfE), Nuthetal
- German Center for Diabetes Research (DZD), Munich
- Institute of Nutrition, University of Potsdam, Nuthetal
| | - Christiane Ott
- Department of Molecular Toxicology, German Institute of Human Nutrition Potsdam-Rehbruecke (DIfE), Nuthetal
- DZHK (German Centre of Cardiovascular Research), partner site Berlin, Germany
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43
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Marcelo A, Brito F, Carmo-Silva S, Matos CA, Alves-Cruzeiro J, Vasconcelos-Ferreira A, Koppenol R, Mendonça L, de Almeida LP, Nóbrega C. Cordycepin activates autophagy through AMPK phosphorylation to reduce abnormalities in Machado-Joseph disease models. Hum Mol Genet 2019; 28:51-63. [PMID: 30219871 DOI: 10.1093/hmg/ddy328] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2018] [Accepted: 09/11/2018] [Indexed: 11/12/2022] Open
Abstract
Machado-Joseph disease (MJD) is a neurodegenerative disorder caused by an abnormal expansion of citosine-adenine-guanine trinucleotide repeats in the disease-causing gene. This mutation leads to an abnormal polyglutamine tract in the protein ataxin-3 (Atx3), resulting in formation of mutant Atx3 aggregates. Despite several attempts to develop a therapeutic option for MJD, currently there are no available therapies capable of delaying or stopping disease progression. Recently, our group reported that reducing the expression levels of mutant Atx3 lead to a mitigation of several MJD-related behavior and neuropathological abnormalities. Aiming a more rapid translation to the human clinics, in this study we investigate a pharmacological inhibitor of translation-cordycepin-in several preclinical models. We found that cordycepin treatment significantly reduced (i) the levels of mutant Atx3, (ii) the neuropathological abnormalities in a lentiviral mouse model, (iii) the motor and neuropathological deficits in a transgenic mouse model and (iv) the number of ubiquitin aggregates in a human neural model. We hypothesize that the effect of cordycepin is mediated by the increase of phosphorylated adenosine monophosphate-activated protein kinase (AMPK) levels, which is accompanied by a reduction in the global translation levels and by a significant activation of the autophagy pathway. Overall, this study suggests that cordycepin might constitute an effective and safe therapeutic approach for MJD, and probably for the other polyglutamine diseases.
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Affiliation(s)
- Adriana Marcelo
- Centre for Biomedical Research (CBMR), University of Algarve, Portugal.,Department of Biomedical Sciences and Medicine (DCBM), University of Algarve, Portugal.,Algarve Biomedical Center (ABC), University of Algarve and University Hospital of Algarve, Portugal.,Center for Neuroscience and Cell Biology (CNC), University of Coimbra, Portugal
| | - Filipa Brito
- Center for Neuroscience and Cell Biology (CNC), University of Coimbra, Portugal
| | - Sara Carmo-Silva
- Center for Neuroscience and Cell Biology (CNC), University of Coimbra, Portugal
| | - Carlos A Matos
- Center for Neuroscience and Cell Biology (CNC), University of Coimbra, Portugal.,Institute for Interdisciplinary Research, University of Coimbra, Portugal
| | - João Alves-Cruzeiro
- Center for Neuroscience and Cell Biology (CNC), University of Coimbra, Portugal
| | | | - Rebekah Koppenol
- Centre for Biomedical Research (CBMR), University of Algarve, Portugal
| | - Liliana Mendonça
- Center for Neuroscience and Cell Biology (CNC), University of Coimbra, Portugal
| | - Luís Pereira de Almeida
- Center for Neuroscience and Cell Biology (CNC), University of Coimbra, Portugal.,Faculty of Pharmacy, University of Coimbra, Portugal
| | - Clévio Nóbrega
- Centre for Biomedical Research (CBMR), University of Algarve, Portugal.,Department of Biomedical Sciences and Medicine (DCBM), University of Algarve, Portugal.,Algarve Biomedical Center (ABC), University of Algarve and University Hospital of Algarve, Portugal.,Center for Neuroscience and Cell Biology (CNC), University of Coimbra, Portugal
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44
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Santana RAG, Oliveira MC, Cabral I, Junior RCAS, de Sousa DRT, Ferreira L, Lacerda MVG, Monteiro WM, Abrantes P, Guerra MDGVB, Silveira H. Anopheles aquasalis transcriptome reveals autophagic responses to Plasmodium vivax midgut invasion. Parasit Vectors 2019; 12:261. [PMID: 31126324 PMCID: PMC6534896 DOI: 10.1186/s13071-019-3506-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2018] [Accepted: 05/14/2019] [Indexed: 01/23/2023] Open
Abstract
Background Elimination of malaria depends on mastering transmission and understanding the biological basis of Plasmodium infection in the vector. The first mosquito organ to interact with the parasite is the midgut and its transcriptomic characterization during infection can reveal effective antiplasmodial responses able to limit the survival of the parasite. The vector response to Plasmodium vivax is not fully characterized, and its specificities when compared with other malaria parasites can be of fundamental interest for specific control measures. Methods Experimental infections were performed using a membrane-feeding device. Three groups were used: P. vivax-blood-fed, blood-fed on inactivated gametocytes, and unfed mosquitoes. Twenty-four hours after feeding, the mosquitoes were dissected and the midgut collected for transcriptomic analysis using RNAseq. Nine cDNA libraries were generated and sequenced on an Illumina HiSeq2500. Readings were checked for quality control and analysed using the Trinity platform for de novo transcriptome assembly. Transcript quantification was performed and the transcriptome was functionally annotated. Differential expression gene analysis was carried out. The role of the identified mechanisms was further explored using functional approaches. Results Forty-nine genes were identified as being differentially expressed with P. vivax infection: 34 were upregulated and 15 were downregulated. Half of the P. vivax-related differentially expressed genes could be related to autophagy; therefore, the effect of the known inhibitor (wortmannin) and activator (spermidine) was tested on the infection outcome. Autophagic activation significantly reduced the intensity and prevalence of infection. This was associated with transcription alterations of the autophagy regulating genes Beclin, DRAM and Apg8. Conclusions Our data indicate that P. vivax invasion of An. aquasalis midgut epithelium triggers an autophagic response and its activation reduces infection. This suggests a novel mechanism that mosquitoes can use to fight Plasmodium infection. Electronic supplementary material The online version of this article (10.1186/s13071-019-3506-8) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Rosa Amélia Gonçalves Santana
- Programa de Pós-Graduação em Medicina Tropical, Universidade do Estado do Amazonas/Fundação de Medicina Tropical Dr. Heitor Vieira Dourado, Manaus, Brazil
| | - Maurício Costa Oliveira
- Programa de Pós-Graduação em Medicina Tropical, Universidade do Estado do Amazonas/Fundação de Medicina Tropical Dr. Heitor Vieira Dourado, Manaus, Brazil
| | - Iria Cabral
- Programa de Pós-Graduação em Medicina Tropical, Universidade do Estado do Amazonas/Fundação de Medicina Tropical Dr. Heitor Vieira Dourado, Manaus, Brazil
| | - Rubens Celso Andrade Silva Junior
- Programa de Pós-Graduação em Medicina Tropical, Universidade do Estado do Amazonas/Fundação de Medicina Tropical Dr. Heitor Vieira Dourado, Manaus, Brazil
| | - Débora Raysa Teixeira de Sousa
- Programa de Pós-Graduação em Medicina Tropical, Universidade do Estado do Amazonas/Fundação de Medicina Tropical Dr. Heitor Vieira Dourado, Manaus, Brazil
| | - Lucas Ferreira
- Programa de Pós-Graduação em Medicina Tropical, Universidade do Estado do Amazonas/Fundação de Medicina Tropical Dr. Heitor Vieira Dourado, Manaus, Brazil
| | - Marcus Vinícius Guimarães Lacerda
- Programa de Pós-Graduação em Medicina Tropical, Universidade do Estado do Amazonas/Fundação de Medicina Tropical Dr. Heitor Vieira Dourado, Manaus, Brazil.,Instituto Leônidas & Maria Deane, Fundação Oswaldo Cruz, Manaus, Brazil
| | - Wuelton Marcelo Monteiro
- Programa de Pós-Graduação em Medicina Tropical, Universidade do Estado do Amazonas/Fundação de Medicina Tropical Dr. Heitor Vieira Dourado, Manaus, Brazil
| | - Patrícia Abrantes
- Instituto de Higiene e Medicina Tropical, Global Health and Tropical Medicine, Universidade Nova de Lisboa, Lisboa, Portugal
| | - Maria das Graças Vale Barbosa Guerra
- Programa de Pós-Graduação em Medicina Tropical, Universidade do Estado do Amazonas/Fundação de Medicina Tropical Dr. Heitor Vieira Dourado, Manaus, Brazil
| | - Henrique Silveira
- Programa de Pós-Graduação em Medicina Tropical, Universidade do Estado do Amazonas/Fundação de Medicina Tropical Dr. Heitor Vieira Dourado, Manaus, Brazil. .,Instituto de Higiene e Medicina Tropical, Global Health and Tropical Medicine, Universidade Nova de Lisboa, Lisboa, Portugal.
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45
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Kohno S, Shiozaki Y, Keenan AL, Miyazaki-Anzai S, Miyazaki M. An N-terminal-truncated isoform of FAM134B (FAM134B-2) regulates starvation-induced hepatic selective ER-phagy. Life Sci Alliance 2019; 2:2/3/e201900340. [PMID: 31101736 PMCID: PMC6526285 DOI: 10.26508/lsa.201900340] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2019] [Revised: 05/07/2019] [Accepted: 05/07/2019] [Indexed: 12/20/2022] Open
Abstract
This study has identified a novel truncated isoform of FAM134B (FAM134B-2) that regulates starvation-induced selective ER-phagy of secretory proteins such as ApoCIII through the activation of C/EBPβ. Autophagy is a conserved system that adapts to nutrient starvation, after which proteins and organelles are degraded to recycle amino acids in response to starvation. Recently, the ER was added to the list of targets of autophagic degradation. Autophagic degradation pathways of bulk ER and the specific proteins sorted through the ER are considered key mechanisms in maintaining ER homeostasis. Four ER-resident proteins (FAM134B, CCPG1, SEC62, and RTN3) have been identified as ER-resident cargo receptors, which contain LC3-interacting regions. In this study, we identified an N-terminal–truncated isoform of FAM134B (FAM134B-2) that contributes to starvation-induced ER-related autophagy. Hepatic FAM134B-2 but not full-length FAM134B (FAM134B-1) is expressed in a fed state. Starvation drastically induces FAM134B-2 but no other ER-resident cargo receptors through transcriptional activation by C/EBPβ. C/EBPβ overexpression increases FAM134B-2 recruitment into autophagosomes and lysosomal degradation. FAM134B-2 regulates lysosomal degradation of ER-retained secretory proteins such as ApoCIII. This study demonstrates that the C/EBPβ-FAM134B-2 axis regulates starvation-induced selective ER-phagy.
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Affiliation(s)
- Shohei Kohno
- Division of Renal Diseases and Hypertension, Department of Medicine, University of Colorado Denver, Aurora, CO, USA
| | - Yuji Shiozaki
- Division of Renal Diseases and Hypertension, Department of Medicine, University of Colorado Denver, Aurora, CO, USA
| | - Audrey L Keenan
- Division of Renal Diseases and Hypertension, Department of Medicine, University of Colorado Denver, Aurora, CO, USA
| | - Shinobu Miyazaki-Anzai
- Division of Renal Diseases and Hypertension, Department of Medicine, University of Colorado Denver, Aurora, CO, USA
| | - Makoto Miyazaki
- Division of Renal Diseases and Hypertension, Department of Medicine, University of Colorado Denver, Aurora, CO, USA
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46
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Di Pardo A, Pepe G, Castaldo S, Marracino F, Capocci L, Amico E, Madonna M, Giova S, Jeong SK, Park BM, Park BD, Maglione V. Stimulation of Sphingosine Kinase 1 (SPHK1) Is Beneficial in a Huntington's Disease Pre-clinical Model. Front Mol Neurosci 2019; 12:100. [PMID: 31068790 PMCID: PMC6491579 DOI: 10.3389/fnmol.2019.00100] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2019] [Accepted: 04/03/2019] [Indexed: 12/19/2022] Open
Abstract
Although several agents have been identified to provide therapeutic benefits in Huntington disease (HD), the number of conventionally used treatments remains limited and only symptomatic. Thus, it is plausible that the need to identify new therapeutic targets for the development of alternative and more effective treatments is becoming increasingly urgent. Recently, the sphingosine-1-phosphate (S1P) axis has been reported to be a valid potential novel molecular target for therapy development in HD. Modulation of aberrant metabolism of S1P in HD has been proved to exert neuroprotective action in vitro settings including human HD iPSC-derived neurons. In this study, we investigated whether promoting S1P production by stimulating Sphingosine Kinase 1 (SPHK1) by the selective activator, K6PC-5, may have therapeutic benefit in vivo in R6/2 HD mouse model. Our findings indicate that chronic administration of 0.05 mg/kg K6PC-5 exerted an overall beneficial effect in R6/2 mice. It significantly slowed down the progressive motor deficit associated with disease progression, modulated S1P metabolism, evoked the activation of pro-survival pathways and markedly reduced the toxic mutant huntingtin (mHtt) aggregation. These results suggest that K6PC-5 may represent a future therapeutic option in HD and may potentially counteract the perturbed brain function induced by deregulated S1P pathways.
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Affiliation(s)
| | | | | | | | | | | | | | | | - Se Kyoo Jeong
- Department of Cosmetic Science, Seowon University, Cheongju, South Korea
| | - Bu-Mahn Park
- NeoPharm USA Inc., Engelwood Cliffs, NJ, United States
| | - Byeong Deog Park
- Dr. Raymond Laboratories, Inc., Englewood Cliffs, NJ, United States
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Lee JH, Rao MV, Yang DS, Stavrides P, Im E, Pensalfini A, Huo C, Sarkar P, Yoshimori T, Nixon RA. Transgenic expression of a ratiometric autophagy probe specifically in neurons enables the interrogation of brain autophagy in vivo. Autophagy 2019; 15:543-557. [PMID: 30269645 PMCID: PMC6351128 DOI: 10.1080/15548627.2018.1528812] [Citation(s) in RCA: 43] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2018] [Revised: 09/14/2018] [Accepted: 09/19/2018] [Indexed: 10/28/2022] Open
Abstract
Autophagy-lysosome pathway (ALP) disruption is considered pathogenic in multiple neurodegenerative diseases; however, current methods are inadequate to investigate macroautophagy/autophagy flux in brain in vivo and its therapeutic modulation. Here, we describe a novel autophagy reporter mouse (TRGL6) stably expressing a dual-fluorescence-tagged LC3 (tfLC3, mRFP-eGFP-LC3) by transgenesis selectively in neurons. The tfLC3 probe distributes widely in the central nervous system, including spinal cord. Expression levels were similar to endogenous LC3 and induced no detectable ALP changes. This ratiometric reporter registers differential pH-dependent changes in color as autophagosomes form, fuse with lysosomes, acidify, and degrade substrates within autolysosomes. We confirmed predicted changes in neuronal autophagy flux following specific experimental ALP perturbations. Furthermore, using a third fluorescence label in TRGL6 brains to identify lysosomes by immunocytochemistry, we validated a novel procedure to detect defective autolysosomal acidification in vivo. Thus, TRGL6 mice represent a unique tool to investigate in vivo ALP dynamics in specific neuron populations in relation to neurological diseases, aging, and disease modifying agents. Abbreviations: ACTB: actin, beta; AD: Alzheimer disease; AL: autolysosomes; ALP: autophagy-lysosome pathway; AP: autophagosome; APP: amyloid beta (Abeta) precursor protein; ATG5: autophagy related 5; ATG7: autophagy related 7; AV: autophagic vacuoles; CNS: central nervous system; CTSD: cathepsin D; CQ: chloroquine; DMEM: Dulbecco's modified Eagle's medium; GFP: green fluorescent protein; GABARAP: gamma-aminobutyric acid receptor associated protein; GABARAPL2/GATE16: gamma-aminobutyric acid (GABA) receptor-associated protein-like 2; ICC: immunocytochemistry; ICV: intra-cerebroventricular; LAMP2: lysosomal-associated membrane protein 2; Leup: leupeptin; LY: lysosomes; MAP1LC3/LC3: microtubule-associated protein 1 light chain 3; MTOR: mechanistic target of rapamycin kinase; RBFOX3/NeuN: RNA binding protein, fox-1 homolog (C. elegans) 3; RFP: red fluorescent protein; RPS6KB1: ribosomal protein S6 kinase, polypeptide 1; SDS-PAGE: sodium dodecyl sulfate-polyacrylamide gel electrophoresis; SQSTM1: sequestosome 1; tfLC3: mRFP-eGFP-LC3; TRGL6: Thy1 mRFP eGFP LC3-line 6; PCR: polymerase chain reaction; PD: Parkinson disease.
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Affiliation(s)
- Ju-Hyun Lee
- Center for Dementia Research, Nathan S. Kline Institute, Orangeburg, NY, USA
- Department of Psychiatry, New York University, New York, NY, USA
| | - Mala V. Rao
- Center for Dementia Research, Nathan S. Kline Institute, Orangeburg, NY, USA
- Department of Psychiatry, New York University, New York, NY, USA
| | - Dun-Sheng Yang
- Center for Dementia Research, Nathan S. Kline Institute, Orangeburg, NY, USA
- Department of Psychiatry, New York University, New York, NY, USA
| | - Philip Stavrides
- Center for Dementia Research, Nathan S. Kline Institute, Orangeburg, NY, USA
| | - Eunju Im
- Center for Dementia Research, Nathan S. Kline Institute, Orangeburg, NY, USA
- Department of Psychiatry, New York University, New York, NY, USA
| | - Anna Pensalfini
- Center for Dementia Research, Nathan S. Kline Institute, Orangeburg, NY, USA
- Department of Psychiatry, New York University, New York, NY, USA
| | - Chunfeng Huo
- Center for Dementia Research, Nathan S. Kline Institute, Orangeburg, NY, USA
| | - Pallabi Sarkar
- Center for Dementia Research, Nathan S. Kline Institute, Orangeburg, NY, USA
| | | | - Ralph A. Nixon
- Center for Dementia Research, Nathan S. Kline Institute, Orangeburg, NY, USA
- Department of Psychiatry, New York University, New York, NY, USA
- Department of Cell Biology, New York University, New York, NY, USA
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Miyake S, Takihara Y, Yokota S, Takamura Y, Inatani M. Effect of Microtubule Disruption on Dynamics of Acidic Organelles in the Axons of Primary Cultured Retinal Ganglion Cells. Curr Eye Res 2017; 43:77-83. [PMID: 28937869 DOI: 10.1080/02713683.2017.1370117] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
PURPOSE Axonal transport is fundamental to autophagy in neuronal cells. To understand its biological significance in various conditions, it is necessary to monitor the process of autophagy. However, monitoring methods are often limited to static analyses, such as protein expression and histological observations. Autophagy has multistep process and is highly dynamic; therefore, additional techniques are necessary to study autophagy. In this study, we quantified the dynamics of autophagy-related organelle transport under conditions of dynamic instability and catastrophic disruption of microtubules using in vitro live imaging. MATERIALS AND METHODS Retinal ganglion cells (RGCs) were isolated from postnatal day 3 Sprague-Dawley rats by immunopanning. After 7 days of culture, acidic organelles were stained by LysoTracker. Dynamics of acidic organelles was quantified using kymographs. Colchicine was used to induce microtubule disruption. Movement of acidic organelles was observed at five time points: before, and at 6, 24, 72, and 120 h after colchicine stimulation. Ethidium homodimer-1 (EthD-1) was used to determine cell viability. RESULTS The status of axonal transport of acidic organelles (n = 363) from 27 RGCs was classified into four categories: anterograde (1.4%), retrograde (90%), stationary (8.0%), and fluttering (0.28%). Six hours after the induction of microtubule disruption in 14 of 27 RGCs, almost all acidic organelles (n = 236) were stationary. All acidic components had completely stopped moving 24 h later. At 72 h after stimulation, axonal fragmentation, and shrinking and disappearance of soma were observed in 71% of RGCs. Finally, the remaining RGCs became positive for EthD-1. In the control (13 of 27 RGCs), axonal transport was maintained for 120 h and EthD-1-positive RGCs were not observed. CONCLUSION Almost all acidic organelles were transported retrogradely along the axon, which was inhibited by colchicine. Understanding the dynamics of acidic organelles may provide useful parameters for characterizing autophagy of neuronal cells in pathophysiological conditions.
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Affiliation(s)
- Seiji Miyake
- a Department of Ophthalmology, Faculty of Medical Sciences , University of Fukui , Fukui , Japan
| | - Yuji Takihara
- a Department of Ophthalmology, Faculty of Medical Sciences , University of Fukui , Fukui , Japan.,b Cancer Science Institute of Singapore , National University of Singapore , Medical Drive , Singapore
| | - Satoshi Yokota
- a Department of Ophthalmology, Faculty of Medical Sciences , University of Fukui , Fukui , Japan.,c Department of Ophthalmology and Visual Sciences , Kyoto University Graduate School of Medicine , Kyoto , Japan
| | - Yoshihiro Takamura
- a Department of Ophthalmology, Faculty of Medical Sciences , University of Fukui , Fukui , Japan
| | - Masaru Inatani
- a Department of Ophthalmology, Faculty of Medical Sciences , University of Fukui , Fukui , Japan
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Monitoring and Measuring Autophagy. Int J Mol Sci 2017; 18:ijms18091865. [PMID: 28846632 PMCID: PMC5618514 DOI: 10.3390/ijms18091865] [Citation(s) in RCA: 746] [Impact Index Per Article: 106.6] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2017] [Revised: 08/12/2017] [Accepted: 08/25/2017] [Indexed: 12/31/2022] Open
Abstract
Autophagy is a cytoplasmic degradation system, which is important for starvation adaptation and cellular quality control. Recent advances in understanding autophagy highlight its importance under physiological and pathological conditions. However, methods for monitoring autophagic activity are complicated and the results are sometimes misinterpreted. Here, we review the methods used to identify autophagic structures, and to measure autophagic flux in cultured cells and animals. We will also describe the existing autophagy reporter mice that are useful for autophagy studies and drug testing. Lastly, we will consider the attempts to monitor autophagy in samples derived from humans.
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